Supplier SBOM Submission Guide
An SBOM generation and submission guide for partner companies that supply software to SK Telecom.
To strengthen the transparency and security of its software supply chain, SK Telecom asks suppliers to submit an SBOM (Software Bill of Materials) for all software components and dependencies they deliver. This guide explains how suppliers can generate and submit an SBOM in a format that meets SK Telecom’s security policy.
Quick Start: Five Steps to Submission
- Check the accepted formats (CycloneDX JSON recommended) and required data fields in the Submission Requirements.
- Generate the SBOM following How to Generate an SBOM, choosing the tool that fits your delivery. If setting up a tool environment is a burden, we recommend BomLens.
- If you deliver a server with an application on top of an OS, generate per layer and merge, following Server SBOM.
- Verify PURLs and transitive dependency coverage with the Validation Checklist.
- Name the file and submit it following the Submission Process.
If you supply commercial software or a finished product made by a third party and have no access to the source code, skip steps 2–3 and follow Commercial Software to obtain the SBOM from the manufacturer and submit it. If your submission is rejected, check Common Rejection Reasons for the cause and how to fix it.
Scope of Application
All suppliers (including developers and resellers) that deliver the following types of software are subject to these guidelines.
- Source code: Applications written in Java, Python, JavaScript, Go, C/C++, etc.
- Container images: Docker images or OCI-compliant containers
- Executables: Compiled binaries (.jar, .dll, .so) and libraries
- Embedded systems: Firmware images, RootFS, device drivers
- Servers: A system combining an OS (rootfs and installed packages) with an application and statically linked libraries
- Commercial software and finished products: packaged software or appliances made by a third party (including reseller and distributor deliveries)
SBOM Submission Process
We ask suppliers to follow the procedure below, from the time of contract through final delivery.
flowchart TD
A[Contract Review] --> B["Software Development/Build"]
B --> C{Generate SBOM}
C -->|Use SKT-provided tool| D[Use BomLens]
C -->|Use your own tool| E["Use open source tools<br>(cdxgen, Syft, etc.)"]
C -->|Commercial finished product| K[Obtain the manufacturer's SBOM]
D --> F["Data Validation (PURL Check)"]
E --> F
K --> F
F --> G["Submit SBOM (Email/Designated channel)"]
G --> H[SKT Security Review]
H -->|Approved| I[Delivery Complete]
H -->|Rejected| J[Remediate and Resubmit]
J --> F
classDef start fill:#F2F2F2,stroke:#171717,color:#171717,stroke-width:1.5px
classDef proc fill:#ffffff,stroke:#c8c8c8,color:#171717,stroke-width:1px
classDef decision fill:#FFF3CD,stroke:#E0A800,color:#5A4100,stroke-width:1.5px
classDef good fill:#D9F0E4,stroke:#00A651,color:#0A5A32,stroke-width:1.5px
classDef danger fill:#FDE1E7,stroke:#EA002C,color:#8A0019,stroke-width:1.5px
classDef vendor fill:#FFF3CD,stroke:#E0A800,color:#5A4100,stroke-width:1.5px
class A start
class B,E,F,G proc
class C,H decision
class D,I good
class J danger
class K vendor1 - SBOM Submission Requirements
Defines in detail the standard SBOM format, required information, and PURL identifier rules under SK Telecom policy.
SK Telecom supports both formats that have become established as global standards. Suppliers may choose and submit the format supported by the tool they use.
| Format | Version | Recommended Use | File Format |
|---|
| CycloneDX | v1.3, v1.4, v1.5, v1.6 | Application security, vulnerability management focus | JSON (recommended), XML |
| SPDX | v2.2, v2.3 | License compliance focus | JSON, Tag-Value |
Note: Both formats are recognized equally, but CycloneDX (JSON) format is recommended for internal system interoperability.
Requirement Levels at a Glance
The requirement level of each item. A missing required item leads to rejection. A missing recommended item does not, but including it is encouraged.
| Item | Level | Details |
|---|
| Standard format and version (CycloneDX or SPDX) | Required | 1. Standard Data Formats |
| Metadata (timestamp, generation tool, top-level component) | Required | 2.1 Metadata |
| Component name and version | Required | 2.2 Component Information |
| Direct and transitive dependencies | Required | 2.3 Dependency Scope |
PURL (standard pkg: form, no generic) | Required | 3. PURL Compliance |
| Dev-only dependencies | Recommended | 2.3 Dependency Scope |
| License information | Recommended | 4. Sample Documents |
Download the example SBOM file (CycloneDX 1.6 JSON) that meets the acceptance criteria and compare its structure.
The SBOM document you submit must include the following information. Missing information may result in rejection.
Information about the document itself and the generation tool.
- Timestamp: Generation date and time (ISO 8601 format)
- Tool Info: Vendor, name, and version of the generation tool (e.g.,
CycloneDX-Maven-Plugin v2.7.9) - Component Info: Name and version of the top-level software being delivered
Generation tool information must be recorded in the following fields depending on the format.
- SPDX: Record the tool name and version in the
creationInfo.creators field with the Tool: prefix - CycloneDX: Record
vendor, name, and version in the metadata.tools array
// SPDX creationInfo example
"creationInfo": {
"created": "2026-04-06T03:22:00Z",
"creators": ["Tool: Syft-0.98.0", "Organization: VendorName"]
}
2.2 Components
Information about the individual libraries that make up the software.
- Name: Component name (e.g.,
commons-lang3) - Version: Component version (e.g.,
3.12.0) — required. Record the exact version in SPDX’s versionInfo field or CycloneDX’s version field; without a version, vulnerability mapping is impossible. - PURL (Package URL): [Required] Package identifier
2.3 Dependency Scope
Important: Transitive dependencies must be included.
SK Telecom analyzes vulnerabilities based on the submitted SBOM. An SBOM that includes only direct dependencies may miss hidden vulnerabilities and may therefore be rejected.
| Dependency Type | Description | Inclusion |
|---|
| Direct | Libraries explicitly declared by the project | Required |
| Transitive | Libraries that the direct dependencies in turn depend on | Required |
| Dev-only | Libraries not included at runtime, such as test and build tools | Inclusion recommended |
What are transitive dependencies?
For example, if a project uses library-A directly, and library-A internally uses library-B, then library-B is a transitive dependency. Even if library-B has a vulnerability, it cannot be detected unless it is included in the SBOM.
Prerequisites for generating a correct SBOM
For transitive dependencies to be included accurately, the SBOM must be generated with the build (or package installation) completed. When only source code is present, transitive dependencies may be omitted.
- Java (Maven): Generate after running
mvn package or mvn dependency:resolve - Java (Gradle): Generate after running
./gradlew dependencies - Python: Generate after
pip install -r requirements.txt (with the virtual environment activated) - Node.js: Generate after running
npm install or yarn install - Go: Generate after running
go mod download
For how to include transitive dependencies with each tool, refer to the Using Open Source Tools guide.
3. Package URL (PURL) Compliance
PURL (Package URL) is a standard URL format for uniquely identifying a software package. SK Telecom’s vulnerability analysis system operates based on PURL, so a valid PURL must be included for every component.
A PURL must be in the standard format beginning with the pkg: prefix. Free text such as name:version or org/repo:tag is not allowed; in such cases vulnerability mapping is impossible and the SBOM will be rejected. The type must identify the ecosystem; pkg:generic/ is not allowed.
PURL Examples by Language
| Ecosystem | PURL Format Example |
|---|
| Java (Maven) | pkg:maven/org.springframework/spring-core@5.3.20 |
| JavaScript (NPM) | pkg:npm/express@4.18.2 |
| Python (PyPI) | pkg:pypi/django@4.1.0 |
| Go | pkg:golang/github.com/gin-gonic/gin@v1.8.1 |
| .NET (NuGet) | pkg:nuget/Newtonsoft.Json@13.0.1 |
| Ruby (RubyGems) | pkg:gem/rails@7.0.4 |
| GitHub (Actions / source hosting) | pkg:github/actions/checkout@v3 |
| OS package (RPM) | pkg:rpm/centos/glibc@2.17-317.el7?arch=x86_64 |
Correct / Incorrect PURL Examples
| Incorrect | Correct |
|---|
commons-lang3:3.12.0 | pkg:maven/org.apache.commons/commons-lang3@3.12.0 |
actions/checkout:v3 | pkg:github/actions/checkout@v3 |
lodash@4.17.21 | pkg:npm/lodash@4.17.21 |
pkg:generic/foo@1.0 | (Change to a type appropriate for the ecosystem) |
For detailed PURL specifications, refer to the official Package URL spec.
4. Sample Document
CycloneDX Sample
{
"bomFormat": "CycloneDX",
"specVersion": "1.6",
"version": 1,
"metadata": {
"timestamp": "2026-04-06T10:30:00Z",
"tools": [{
"vendor": "Example Corp",
"name": "cyclonedx-maven-plugin",
"version": "2.7.9"
}],
"component": {
"type": "application",
"name": "PaymentModule",
"version": "2.1.0",
"purl": "pkg:maven/com.example/payment-module@2.1.0"
}
},
"components": [{
"type": "library",
"name": "spring-core",
"version": "5.3.20",
"purl": "pkg:maven/org.springframework/spring-core@5.3.20",
"licenses": [{
"license": {
"id": "Apache-2.0"
}
}]
}]
}
References
2 - Generating an SBOM with Open Source Tools
Explains how to generate an SBOM for each environment using general-purpose open source tools.
If you are not comfortable setting up a tool environment and you have Docker installed, consider reviewing BomLens first.
graph TD
A{{"Classify the supplied software"}}
subgraph G1["Software delivery"]
direction LR
T1["Source code / app<br>(e.g., OSS/BSS, portals, middleware)"]
T2["Executable / library<br>(e.g., .jar, .dll, .so)"]
T3["Firmware with no OS<br>(e.g., bare-metal / RTOS devices)"]
end
subgraph G2["Delivery including an OS (e.g., Linux)"]
direction LR
T4["Container image<br>(e.g., CNF, containerized network function)"]
T5["Server / VM image<br>(e.g., VNF, server appliance)"]
T6["Firmware with an embedded OS<br>(e.g., base stations, routers, OLT/ONT, set-top boxes)"]
end
%% Left: source-code scan with an inner box
subgraph M1["Scan the source code"]
M1_Sub["cdxgen or BomLens"]
end
%% Right: source + OS image scan with inner boxes (stacked vertically)
subgraph M2["Scan source + OS image"]
direction TB
M2_Top["OS (e.g., Linux) scan<br>(Syft or Trivy)"]
M2_Bottom["Source code scan<br>(cdxgen or BomLens)"]
end
A --> G1
A --> G2
%% Connect only to the group borders (one arrow per box)
G1 --> M1
G2 --> M2
%% Groups flow to the next step
M1 --> P(["Submit the SBOM"])
M2 --> P
classDef start fill:#F2F2F2,stroke:#171717,color:#171717,stroke-width:1.5px
classDef typebox fill:#ffffff,stroke:#c8c8c8,color:#171717,stroke-width:1px
classDef submit fill:#F2F2F2,stroke:#171717,color:#171717,stroke-width:1.5px
%% White inner-box styles (left/right border colors)
classDef subwhite_left fill:#ffffff,stroke:#00A651,color:#171717,stroke-width:1px
classDef subwhite_right fill:#ffffff,stroke:#68127A,color:#171717,stroke-width:1px
class A start
class T1,T2,T3,T4,T5,T6 typebox
class M1_Sub subwhite_left
class M2_Top,M2_Bottom subwhite_right
class P submit
style G1 fill:#F1FAF5,stroke:#00A651,stroke-width:1px,color:#0A5A32
style G2 fill:#FAF4FB,stroke:#68127A,stroke-width:1px,color:#4A0D57
%% Outer group boxes keep their fill and border colors
style M1 fill:#D9F0E4,stroke:#00A651,stroke-width:1px,color:#0A5A32
style M2 fill:#EEDCF3,stroke:#68127A,stroke-width:1px,color:#4A0D57Source code and apps, executables or libraries, and firmware with no OS are all scanned from the source code you developed with cdxgen or BomLens. Scanning a finished binary directly yields no package manager metadata, so purls are omitted and the SBOM is rejected.
When you ship an OS or base image as part of the delivery (a container image, a server, or firmware with an embedded OS), split it into two layers and scan each. Scan the image or rootfs as shipped with Syft or Trivy for the OS layer, scan the source code (the app layer) with cdxgen or BomLens, then merge and submit. The OS-layer scan target is not the original base image you received but the image or rootfs actually delivered after the build, because it must include the OS packages installed during the build. For the full procedure, see Server SBOM.
Statically linked libraries and manually vendored binaries are a blind spot that none of the scans above catch. For how to handle this case, see the statically linked libraries section of Server SBOM.
If you supply commercial software or a finished product made by a third party and have no access to the source code, obtain the SBOM from the manufacturer instead of scanning. See Commercial Software.
cdxgen (recommended for source code analysis)
Automatically analyzes projects in various languages such as Java, Python, Node.js, and Go, and generates an SBOM in CycloneDX format.
cdxgen statically parses lockfiles and manifests. For accurate results, run it when dependencies are installed or resolved (a lockfile is present, or after a build). Scanning pure source without resolved dependencies may omit some components or purls.
Syft (recommended for container image and binary analysis)
Analyzes built container images and build artifacts that include package manager metadata to identify both OS packages and application libraries. Supports CycloneDX and SPDX formats.
Warning — Do not scan installation directories or collections of raw files (PURL omission causes full rejection)
If you use syft dir: mode to scan an installation directory or a collection of binaries that has no
package manager metadata (package.json, go.mod, *.jar, RPM/DEB package DB, etc.), Syft cannot
identify the ecosystem and produces an SBOM with empty PURLs. Because SK Telecom’s system maps
vulnerabilities by PURL, such an SBOM fails matching entirely and is rejected.
For a real case rejected this way, see Common Rejection Reasons.
Run Syft against the following targets.
# Recommended: scan a built image (PURL and ecosystem identified automatically)
syft <image-name>:<tag> -o cyclonedx-json=sbom.json
# Not recommended: scan an installation directory or raw files (rejected due to missing PURL)
syft dir:/root/nag_pkg # without package manager metadata, PURL count becomes 0
Immediately after generation, be sure to check the PURL count. See the Validation Checklist for how to verify.
A server that delivers an application on top of an OS (such as CentOS) is generated as two layers — OS (rootfs/image) and application — with statically linked libraries covered separately, then merged. As the warning above notes, the OS layer must target a rootfs or image that has a package database. For the full procedure, see Server SBOM.
Trivy (container image analysis)
An all-in-one tool that can perform container image analysis and vulnerability scanning together.
Security Warning — Trivy Supply Chain Attack Incident (2026)
In March 2026, a supply chain attack occurred in which an attacker re-pointed existing release tags
of aquasecurity/trivy to inject malware. The GitHub release v0.69.4 (3/19) and the DockerHub images
v0.69.5 and v0.69.6 (3/22) have been confirmed as compromised, so please stop using them.
To use Trivy safely, follow these principles.
GitHub Actions: Use a pinned commit SHA or a verified version tag instead of mutable tags (@master, @latest, @v1, etc.).
# Recommended: pin to a verified version
- uses: aquasecurity/trivy-action@0.35.0
# Safer: pin to a commit SHA
- uses: aquasecurity/trivy-action@<commit-sha>
Docker images: Specify a particular version tag, or pin to an image digest (@sha256:...).
docker run aquasecurity/trivy:<verified-version> image <target-image>
Official channels: Check the latest security advisories through the GitHub Security Advisory.
This incident shows that if you do not pin versions when adopting an open source tool, you can be exposed to a supply chain attack at any time. Always specify the version of every external tool and verify its integrity before use.
Language-Specific Dedicated Plugins
Using a build tool plugin lets you extract more accurate dependency information.
| Language/Build Tool | Plugin/Tool | Official Documentation |
|---|
| Java (Maven) | cyclonedx-maven-plugin | Link |
| Java (Gradle) | cyclonedx-gradle-plugin | Link |
| Python | cyclonedx-bom | Link |
| Node.js | @cyclonedx/cyclonedx-npm | Link |
| Go | cyclonedx-gomod | Link |
Common Precautions
Verify the following before using a tool.
- Transitive dependency inclusion: Generate the SBOM after the build (package installation) is complete so that transitive dependencies are included. Missing dependencies are grounds for rejection; for the per-language build commands to run first, see the dependency scope section of the Submission Requirements.
- PURL inclusion: Verify that the generated SBOM includes a
purl field for every component. SK Telecom’s system maps vulnerabilities based on PURL. For the verification commands and the regeneration procedure, see the Validation Checklist. - Output format: CycloneDX JSON format is recommended. (Use
-o cyclonedx-json or an equivalent option) - Project information: Verify that the metadata accurately records the name and version of the delivered project.
3 - BomLens
Explains how to generate an SBOM that meets SK Telecom policy using BomLens.
BomLens
BomLens is an open source tool that lets suppliers generate deliverables that meet SK Telecom policy in a Docker environment. You do not need to install per-language tools locally; it analyzes multiple languages and produces a CycloneDX (JSON) deliverable.
This page covers only the quick start. For installation, the full set of options, language-specific guides, input scenarios, the web UI, and other details, see the official repository documentation.
github.com/sktelecom/bomlens
Bug reports, feature suggestions, and Pull Request contributions are welcome.
Deliverables Generated
A single run generates the following three deliverables together (the --all option).
| Deliverable | File | Purpose |
|---|
| SBOM | {project}_{version}_bom.json | CycloneDX 1.6 component specification (the delivery baseline) |
| Open Source Notice | {project}_{version}_NOTICE.{txt,html} | Notice document for fulfilling license obligations |
| Open Source Risk Analysis Report | {project}_{version}_risk-report.{md,html} | Aggregation of license and vulnerability risks |
Prerequisites
BomLens runs on Docker. Install and run Docker Engine 20.10 or later. On Windows without Docker, we recommend Rancher Desktop, which is free. The first run downloads a scanner image (about 3–4 GB), so it takes roughly 5–15 minutes.
Getting Started on Windows (No Command Line)
If you are not comfortable with the command line, you can generate an SBOM in one of two ways. For the full procedure, see the no command line quick start.
- Executable: Download
SBOM-Generator-*.exe (the BomLens executable) from the latest release and double-click it. The file is not yet code-signed, so if Windows SmartScreen warns, click “More info” and then “Run anyway”. - Repository ZIP: From the repository’s
Code button, choose Download ZIP, unzip it, and double-click scripts\sbom-ui.bat; the browser opens http://localhost:8080.
In the web UI, the progress log is shown in real time on the right, and you can download the deliverables when it finishes.

Quick Start (CLI)
On macOS and Linux, download and run the script from a shell.
curl -O https://raw.githubusercontent.com/sktelecom/bomlens/main/scripts/scan-sbom.sh
chmod +x scan-sbom.sh
cd /path/to/my-project
/path/to/scan-sbom.sh --project "MyApp" --version "1.0.0" --all --generate-only
--generate-only creates files only locally, without submitting them (recommended until submission).- For the web UI, run
./scan-sbom.sh --ui (the browser opens http://localhost:8080). - On Windows, run the same commands through
scripts\scan-sbom.bat (it forwards them via Git Bash, so Git for Windows is required). - For other input forms such as a GitHub URL, source ZIP, Docker image, firmware, or binary, and the full set of options, see the CLI reference.
Learn More
The authoritative source for using the tool is the repository documentation.
Next Steps
After generating the SBOM, verify the file with the Validation Checklist and submit it following the Submission Process. For the required data fields, see the Submission Requirements; to use tools such as cdxgen or Syft directly instead of the SKT tool, see Using Open Source Tools.
4 - Generating a Server (OS + Application) SBOM
How to build the SBOM for a delivered server — scan the OS and the application as two layers, cover statically linked libraries separately as a blind spot, then merge them into one BOM for submission.
This document is an advanced guide for suppliers that deliver a server with an application on top of an OS. For an ordinary application delivery, How to Generate an SBOM is sufficient.
Treat the server as two layers — the OS and the application — generate each separately, then merge them. Both are produced with BomLens; only the input changes. In addition, statically linked libraries (for example an openssl built into the binary) are a blind spot that neither layer’s scan catches, so they are handled separately. Missing them is the most common cause of rejection in server delivery.
The two layers of a server
| Layer | What it covers | Symptom if omitted |
|---|
| OS | The OS and its installed packages (e.g. CentOS plus everything in the rpm database) | OS vulnerabilities missing |
| Application | The delivered application and its package-manager dependencies, direct and transitive | Application dependencies missing |
Generating each layer
The commands below use BomLens’s scan-sbom.sh script. For installing BomLens and its basics (downloading the script, the options, the web UI, and so on), see BomLens first. If you use open source tools directly instead of BomLens, scan the OS layer with Syft (or Trivy) and the application layer with cdxgen; see Using Open Source Tools for the commands.
OS layer
Scan the server’s rootfs (the extracted root filesystem) or a container image of it. The target must be the delivered, built state — not the base image you started from — because the OS packages installed during the build have to be included. The package database (rpm/dpkg/apk) is read so every installed package gets a real purl (pkg:rpm/...).
# Target a rootfs directory
scan-sbom.sh --project myserver-os --version 7 --target /path/to/server-rootfs --all --generate-only
# Or, if the server is packaged as a container image
scan-sbom.sh --project myserver-os --version 7 --target myserver:7 --all --generate-only
The target must contain the package database. A folder holding only unpacked install files, with no rpm database, yields empty purls and is rejected.
Application layer
Scan the application source after the build. With a package manager (Maven, npm, pip, Go modules, Conan, and others), transitive dependencies resolve automatically.
cd /path/to/app-source
scan-sbom.sh --project myserver-app --version 2.0.0 --all --generate-only
A pure CMake/Make application with no manifest produces a sparse component list; add --deep-license to record the first-party source licenses.
Static-link libraries (a blind spot)
Statically linked libraries are not declared by a package manager and not listed in the OS package database, so neither layer’s scan finds them. There is no fully automatic path, so combine two approaches. Analyze the delivered binary for what tooling can find, and for what it still misses, record the source and version by hand from the build script (for example openssl 1.1.1za).
scan-sbom.sh --project myserver-bin --version 2.0.0 --target /path/to/delivered-binary --all --generate-only
A precise inventory of statically linked components comes from binary composition analysis (BDBA), which SK Telecom runs as a complementary check.
Merge into one BOM for submission
SK Telecom’s submission system registers one SBOM per product. Merge the per-layer SBOMs with --merge into a single BOM and stamp the top-level component with the delivered product name and version. --merge dedupes by purl, so a library appearing in more than one layer is counted once.
scan-sbom.sh --project myserver --version 1.0.0 \
--merge myserver-os_7_bom.json myserver-app_2.0.0_bom.json myserver-bin_2.0.0_bom.json \
--generate-only
If the whole server is delivered as a single container image, you can scan that image with --target to capture the OS and application layers together.
Keep the per-layer SBOMs for review
The official submission is the merged single BOM, but the per-layer SBOMs show at a glance which layer is missing or vulnerable, so they are useful for your own review and for responding to rejections. Keep them.
Multi-node clusters
A product in which multiple nodes form one cluster is still submitted as one SBOM per product; you do not need one per node.
- If every node has the same configuration, generate and merge the layers from one representative node.
- If the installed software differs by node role (for example, a management node and storage nodes), generate the per-layer SBOMs for each role, then merge everything into a single BOM with
--merge.
Verify before submitting
Check that components carry real purls in both the per-layer SBOMs and the merged one. For the verification commands and the full check, follow the Validation Checklist.
Learn more
The detailed procedure and examples for server delivery live in the canonical BomLens documentation.
Server delivery guide
5 - Submitting an SBOM for Commercial Software and Finished Products
How to obtain an SBOM from the manufacturer and submit it when you supply commercial software or a finished product made by a third party.
This document is for suppliers that deliver commercial software or finished products they did not develop. In this case the supplier has no access to the source code, so the source-scan approach in How to Generate an SBOM does not apply. Obtain the SBOM from the original manufacturer and submit it.
Scanning the delivered equipment or its installed image with a tool is not an alternative. The commercial software has no package manager metadata, so its components come out without purls, vulnerability matching fails, and the SBOM is rejected.
Scope
This applies when you supply third-party products in forms such as the following.
- Commercial software resale: supplying licenses for packaged software developed by a third party (resellers, distributors)
- Appliances and finished products: equipment shipped by the manufacturer with the OS and software preinstalled (e.g., storage, backup appliances, network equipment)
- Systems that include third-party products: deliveries combining in-house components with commercial products
If part of the delivery is developed in-house, generate the SBOM for that part yourself following How to Generate an SBOM, and submit the manufacturer’s SBOM for the commercial part alongside it.
Obtaining the SBOM from the manufacturer
Request an SBOM in CycloneDX or SPDX format from the original manufacturer (or developer). With regulations such as US Executive Order 14028 and the EU Cyber Resilience Act in force, most global manufacturers now have a process for providing per-product SBOMs. Including the following in your request speeds up the response.
- Format: CycloneDX JSON (recommended) or SPDX
- Target: the exact model name and version of the delivered product
- Coverage: if the product ships with an OS, the OS packages must be included
Whether and how quickly a manufacturer can provide an SBOM varies, so request it during contract review to stay on the delivery schedule.
Checking the received SBOM
An SBOM received from the manufacturer is reviewed by the same criteria as one you generate yourself. Before submitting, check the following.
- Compliance with the Submission Requirements: standard format and version, metadata, component names and versions, purls
- The Validation Checklist: purl coverage and the other required items
- Version match: the top-level component in the SBOM matches the name and version of the product actually delivered
Then name the file and submit it following the Submission Process.
If the product is a cluster
A product in which multiple nodes form one cluster (for example, distributed storage) is still submitted as one SBOM per product. For how to determine the SBOM unit, see the multi-node cluster section of Server SBOM.
If the manufacturer cannot provide an SBOM
If the manufacturer replies that it cannot provide an SBOM, contact opensource@sktelecom.com before generating and submitting one by other means.
6 - Pre-Submission SBOM Validation Checklist
Check the essential items before submitting an SBOM to prevent rejection.
Essential Checklist Items
An SBOM that does not pass the checklist below may be automatically rejected by the system. Items 2 through 4 can be checked at once with BomLens automated validation under Validation Tools below.
1. File Integrity
2. Required Data Fields
3. Dependency Completeness Check
Missing transitive dependencies are the most common reason for rejection. Be sure to verify the items below.
4. Identifier (PURL) Check
SK Telecom’s system maps vulnerabilities by PURL. This is the most important item.
Use the commands below to check the PURL count directly. The total component count and the PURL-bearing count should be equal.
# CycloneDX — the two values should be equal
jq '.components | length' sbom.json # total component count
jq '[.components[] | select(.purl)] | length' sbom.json # count with a PURL
# SPDX — number of packages that have a PURL (externalRef)
jq '[.packages[] | select(.externalRefs[]?.referenceType == "purl")] | length' sbom.json
If the PURL-bearing count is 0 or significantly lower than the total component count, do not submit. For the cause and how to regenerate, see Common Rejection Reasons.
BomLens Automated Validation (Recommended)
The SBOM analysis feature of BomLens automatically checks the Submission Requirements, covering items 2 through 4 of the checklist above. Version 1.8.0 or later is required.
./scripts/scan-sbom.sh --project my-app --version 1.0.0 \
--analyze "./sbom.json" \
--generate-only
Running it produces a conformance report (my-app_1.0.0_conformance.html) in the my-app_1.0.0/ folder. The report automatically verifies the following items.
| Check | Checklist Item |
|---|
| Spec version range (CycloneDX 1.3–1.6, SPDX 2.2–2.3) | 2. Required Data Fields |
| Creation timestamp, generating tool, top-level component name and version | 2. Required Data Fields |
| Name and version of every component | 2. Required Data Fields |
| Direct and transitive dependencies included | 3. Dependency Completeness Check |
PURL coverage, standard format (pkg:type/name@version), no pkg:generic | 4. Identifier (PURL) Check |
| License and hash coverage (recommended items) | — |
If the result is fail, the report lists which components fall short on which item, so you can fix those parts, regenerate the SBOM, and validate again. The same validation is available in the web UI (run with --ui and upload the SBOM).
CycloneDX Validator (Schema Check)
An online tool that checks whether a CycloneDX file conforms to the standard schema. It is useful for quickly checking JSON syntax and format errors (checklist item 1) without installing anything. However, it performs schema validation only — passing it does not mean items 2 through 4 (required fields, dependency completeness, PURL) are met. It cannot check SPDX files.
7 - SBOM Submission Process
Explains the submission channels for the prepared SBOM file, the email template, and the post-submission process.
1. When to Submit
- At initial delivery after concluding a software contract
- When a major or minor version of the software is updated
- When a regular submission schedule specified in the contract arrives
2. How to Submit
The SBOM file is submitted to SK Telecom’s business unit and security team representatives via email (or a channel designated by the representative).
- Email subject:
[SBOM Submission] SupplierName_ProjectName_Version - Attachment: The generated SBOM file (password-protected archive files are not allowed)
Required information in the body:
- Delivery contract number
- Representative information (name, department, contact)
- Project information (system name, detailed version)
- Tool used and its version (e.g., BomLens, cdxgen)
3. Post-Submission Validation and Actions
The submitted SBOM is registered in TOSCA, the internal open source and SBOM management system, and then validated according to the procedure below. TOSCA is an internal system, so suppliers do not need access to it.
| Stage | Description | Processing Deadline |
|---|
| Format validation | Check for missing required fields. Notify of rejection if not met | Within 3 days of receipt |
| Security vulnerability analysis | Automatically analyze whether Critical/High severity vulnerabilities are detected | - |
| Action request | Request a patch plan or a written justification when serious vulnerabilities are found | Critical: 7 days / High: 30 days |
The validation results and action requests are communicated to the supplier and the security team representative through the business unit representative.
8 - Common Rejection Reasons
The typical reasons a submitted SBOM is rejected, their causes, and how to fix them.
Submitted SBOMs go through format validation and vulnerability analysis, and are rejected if they fall short of the criteria. Below are the rejection reasons that come up repeatedly in actual intake. Review them together with the Validation Checklist before submitting.
Rejection Reasons at a Glance
| Rejection reason | Main cause | How to fix |
|---|
| All PURLs missing | Scanning an installation directory or raw files with no package manager metadata (syft dir:, etc.) | Scan a built image or the source code instead. How to Generate an SBOM |
| Transitive dependencies missing | Scanning source only, before the build (package installation) | Regenerate after the build completes. See the dependency scope section of the Submission Requirements |
pkg:generic/ PURLs | The tool could not identify the ecosystem | Regenerate with ecosystem-specific types. See the PURL section of the Submission Requirements |
| Component versions missing | Incomplete manifests or tool configuration issues | The version field is required. Submission Requirements |
| Only one layer of a server included | Scanning only the OS layer or only the application layer | Generate per layer and merge. Server SBOM |
| Unaccepted format or version | Generated in a format outside the supported range | CycloneDX JSON recommended. Submission Requirements |
| Top-level component info missing | Delivered product name and version not recorded in the metadata | Record the product name and version in the metadata component. Submission Requirements |
Representative Cases
Case 1: All PURLs missing from an installation-directory scan
A supplier scanned an installation directory with syft dir:/root/nag_pkg and submitted an SBOM in which none of the 261 components had a purl; all 251 vulnerability matches failed and the SBOM was rejected outright. When you scan a location without package manager metadata (package.json, go.mod, an RPM/DEB package DB, etc.), the tool cannot identify the ecosystem.
Change the scan target to a built image or the source code, and check the purl count right after generation. The verification commands are in the Validation Checklist.
Case 2: Transitive dependencies missing from a pre-build scan
If a project has several direct dependencies but the SBOM has fewer than 10 components in total, suspect missing transitive dependencies. A typical web application yields tens to hundreds of components once transitive dependencies are included. Completing the build first (npm install, mvn package, and the like) and then generating resolves this.
What a Passing SBOM Looks Like
Download the example file that meets the acceptance criteria and compare its structure. Every component has a purl and a version, and the dependencies array captures both direct and transitive relationships.