GHSA-wwqh-7jm5-gj7w MEDIUM go/github.com/free5gc/pcf

CVE: CVE-2026-44317

Summary

free5GC's PCF POST /npcf-policyauthorization/v1/app-sessions handler panics on a single authenticated request whose ascReqData.suppFeat == "1" (enabling traffic-routing feature negotiation) and whose medComponents entries supply an afAppId but NO AfRoutReq. The create path then calls provisioningOfTrafficRoutingInfo(smPolicy, appID, routeReq, ...) with routeReq == nil and dereferences routeReq.RouteToLocs (and other fields) without a nil check, causing runtime error: invalid memory address or nil pointer dereference. Gin recovery converts the panic into HTTP 500.

The trigger is a single valid authenticated request -- changing only suppFeat from "0" to "1" flips the same shape of POST from a normal 201 Created into a panic-driven 500.

This endpoint requires a valid npcf-policyauthorization OAuth2 access token (PR:L). The PCF process is not killed (Gin recovers); the realized impact is per-request panic-DoS on the app-session create path.

Details

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

• Source repo tag: v4.2.1
• PCF endpoint: http://10.100.200.9:8000
• Validation date: 2026-03-12

Vulnerable handler path:

postAppSessCtxProcedure
 -> medComponents loop
   -> appID := medComp.AfAppId
      routeReq := medComp.AfRoutReq   // nil when AfRoutReq absent
      provisioningOfTrafficRoutingInfo(smPolicy, appID, routeReq, medComp.FStatus)

In provisioningOfTrafficRoutingInfo, routeReq.RouteToLocs, routeReq.UpPathChgSub, and routeReq.AppReloc are dereferenced directly without a nil check. When suppFeat is "0" the traffic-routing branch is not entered and the same input shape returns 201 Created; when suppFeat is "1" the branch is entered and the nil-deref fires.

Code evidence (paths in free5gc/pcf):

• Affected route + dispatch: NFs/pcf/internal/sbi/api_policyauthorization.go
• Create handler path: NFs/pcf/internal/sbi/processor/policyauthorization.go
• Call si

📌 来源: GitHub-Advisory | 🆔 CVE-2026-44317 | 📅 2026-05-08