GHSA-jqfc-gwj5-3w63 MEDIUM go/github.com/free5gc/udr

CVE: CVE-2026-44324

Summary

free5GC's UDR nudr-dr DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscriptions handler panics on a single authenticated request against a fresh UDR instance when the supplied ueId does not exist in UESubsCollection. The processor checks value, ok := udrSelf.UESubsCollection.Load(ueId) and sets a 404 USER_NOT_FOUND problem-details on the miss path, but execution continues and immediately runs value.(*udr_context.UESubsData) -- a Go type assertion on a nil interface, which panics with interface conversion: interface {} is nil, not *context.UESubsData. Gin recovery converts the panic into HTTP 500, but the endpoint remains repeatedly panicable.

This is the no-precondition sibling of free5gc/free5gc#919: same handler, same bug pattern (set pd, do not return, then dereference), but the panic site is the nil-interface type assertion at line 61 instead of the nil-pointer deref at line 69. No earlier EE-subscription create is required.

This endpoint requires a valid nudr-dr OAuth2 access token (PR:L, NOT PR:N), so this is scored as an authenticated panic-DoS, not as an unauth-bypass finding.

Details

Validated against the UDR container in the official Docker compose lab.

• Source repo tag: v4.2.1
• Running Docker image: free5gc/udr:v4.2.1
• Runtime UDR commit: 754d23b0
• Docker validation date: 2026-03-22
• UDR endpoint: http://10.100.200.11:8000

Vulnerable handler (the ok miss path sets pd but does not return; the next line type-asserts the nil interface):

subsId := c.Params.ByName("subsId")
s.Processor().RemoveAmfSubscriptionsInfoProcedure(c, subsId, ueId)

In the processor:

value, ok := udrSelf.UESubsCollection.Load(ueId)
if !ok {
    pd = util.ProblemDetailsNotFound("USER_NOT_FOUND")
}

UESubsData := value.(*udr_context.UESubsData)   // panics: nil interface

When ueId is absent from UESubsCollection, value is the nil interface{} returned by sync.Map.Load

📌 来源: GitHub-Advisory | 🆔 CVE-2026-44324 | 📅 2026-05-08