GHSA-958m-gxmc-mccm — udm
Fix: free5gc/udm#79GHSA-958m-gxmc-mccm is a CWE-209 vulnerability in github.com/free5gc/udm. A fix is available for github.com/free5gc/udm — see the affected versions and patch details below.
free5GC UDM incorrectly returns 500 for empty supi path parameter in DELETE sdm-subscriptions request
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-958m-gxmc-mccm.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/free5gc/udmReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
This is an Improper Error Handling vulnerability with Information Exposure implications.
- Security Impact: The UDM incorrectly converts a downstream 400 Bad Request (from UDR) into a 500 Internal Server Error when handling DELETE requests with an empty
supipath parameter. This leaks internal error handling behavior and makes it difficult for clients to distinguish between client-side errors and server-side failures. - Functional Impact: When a client sends a DELETE request with an empty
supi(e.g., double slashes//in URL path), the UDM forwards the malformed request to UDR, which correctly returns 400. However, UDM propagates this as 500 SYSTEM_FAILURE instead of returning the appropriate 400 error to the client. This violates REST API best practices for DELETE operations. - Affected Parties: All deployments of free5GC v4.0.1 using the UDM Nudm_SDM service with DELETE operations on sdm-subscriptions endpoint.
Patches
Yes, the issue has been patched.
The fix is implemented in PR free5gc/udm#79.
Users should upgrade to the next release of free5GC that includes this commit.
Workarounds
There is no direct workaround at the application level. The recommendation is to apply the provided patch or implement API gateway-level validation to reject DELETE requests with empty path parameters before they reach UDM.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/free5gc/udm | all versions | 1.4.2go get github.com/free5gc/udm@v1.4.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/free5gc/udm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/free5gc/udm to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-958m-gxmc-mccm is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-958m-gxmc-mccm can be triaged on real exposure rather than presence alone.
Tailored to GHSA-958m-gxmc-mccm. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-958m-gxmc-mccm in your dependencies?
O3 Security finds GHSA-958m-gxmc-mccm across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.