Executive brief
Open5GS is an open-source implementation of 5G core network infrastructure used by telecom operators. A vulnerability in the Rx AA-Request handler component allows remote attackers to craft malformed messages containing improperly formatted AVP fields, triggering an out-of-bounds memory read that could lead to service disruption or information disclosure.
Technical details
The vulnerability exists in the pcrf_rx_aar_cb function in src/pcrf/pcrf-rx-path.c where Framed-IP-Address and Framed-IPv6-Prefix AVP fields are processed without proper length validation. An attacker can send a specially crafted AA-Request (Rx protocol) with a malformed Framed-IP-Address shorter than 4 bytes or a Framed-IPv6-Prefix shorter than expected, causing an out-of-bounds read when the code attempts to use these fields as hash keys or dereference them. The attack requires network-level access to the PCRF component and is remotely exploitable. A patch (commit c18dc6938bf63cc7374315d3dca303d92066e746) adds validation to check AVP lengths before use.
Affected products
- Open5GS Open5GS 2.8.0
Timeline
- 2026-08-24: disclosed
- patched: Patch available as commit c18dc6938bf63cc7374315d3dca303d92066e746