Advisories for Golang/Github.com/Free5gc/Udm package

2026

free5GC UDM vulnerable to null byte injection in URL path parameters causing 500 Internal Server Error

Impact This is an Improper Input Validation vulnerability with Denial of Service and Injection implications. Security Impact: A remote attacker can inject null bytes (URL-encoded as %00) into the supi path parameter of the UDM's Nudm_SubscriberDataManagement API. This causes URL parsing failure in Go's net/url package with the error "invalid control character in URL", resulting in a 500 Internal Server Error. This null byte injection vulnerability can be exploited for …

free5GC UDM incorrectly returns 500 for empty supi path parameter in PATCH sdm-subscriptions reques

Impact This is an Improper Error Handling vulnerability with Information Exposure implications, combined with an HTTP Method Translation issue. Security Impact: The UDM incorrectly converts a downstream 400 Bad Request (from UDR) into a 500 Internal Server Error when handling PATCH requests with an empty supi path parameter. Additionally, the UDM incorrectly translates the PATCH method to PUT when forwarding to UDR, indicating a deeper architectural issue. This leaks internal …

free5GC UDM incorrectly returns 500 for empty supi path parameter in DELETE sdm-subscriptions request

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 supi path 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 …

free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference

Impact This is a NULL Pointer Dereference vulnerability leading to Denial of Service. Security Impact: A remote attacker can cause the UDM service to panic and crash by sending a crafted POST request to the /sdm-subscriptions endpoint with a malformed URL path containing path traversal sequences (../) and a large JSON payload. The DataChangeNotificationProcedure function in notifier.go attempts to access a nil pointer without proper validation, causing a complete service …

2025
2023

free5GC udm vulnerable to Invalid Curve Attack

pkg/suci/suci.go in free5GC udm before 1.2.0, when Go before 1.19 is used, allows an Invalid Curve Attack because it may compute a shared secret via an uncompressed public key that has not been validated. An attacker can send arbitrary SUCIs to the UDM, which tries to decrypt them via both its private key and the attacker's public key.