CVE-2020-13901: 
Linux Debian vulnerability analysis and mitigation

A stack-based buffer overflow vulnerability was discovered in janus-gateway (also known as Janus WebRTC Server) through version 0.10.0. The vulnerability exists in the janus_sdp_merge function within sdp.c file (NVD, CVE). The vulnerability was discovered and reported by Mikhail Evdokimov from Digital Security dsec.ru and was disclosed on June 9, 2020.

The vulnerability is a stack-based buffer overflow condition that occurs in the janus_sdp_merge function within the sdp.c file. This function is responsible for processing and merging SDP (Session Description Protocol) data in the WebRTC server (GitHub PR). The issue arises during the SDP merging process, where insufficient bounds checking could lead to a buffer overflow condition.

A successful exploitation of this vulnerability could allow an attacker to cause a buffer overflow condition, potentially leading to arbitrary code execution or denial of service on affected systems. Given that this affects the SDP processing functionality, which is a core component of WebRTC communication, the vulnerability could impact the security of WebRTC sessions handled by the Janus server (GitHub PR).

The vulnerability requires an attacker to send specially crafted SDP data to an affected Janus WebRTC Server. A proof-of-concept exploit has been developed and is publicly available, indicating that the vulnerability is practically exploitable (GitHub PoC).

The vulnerability was fixed in a security update released through GitHub. Users should upgrade to a version of Janus WebRTC Server that includes the security fixes. The fix was implemented through a pull request that specifically addresses the buffer overflow issue in the SDP code (GitHub PR).