Vulnerabilities > CVE-2021-32686 - Race Condition vulnerability in multiple products
Attack vector
NETWORK Attack complexity
HIGH Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP before version 2.11.1, there are a couple of issues found in the SSL socket. First, a race condition between callback and destroy, due to the accepted socket having no group lock. Second, the SSL socket parent/listener may get destroyed during handshake. Both issues were reported to happen intermittently in heavy load TLS connections. They cause a crash, resulting in a denial of service. These are fixed in version 2.11.1.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Leveraging Race Conditions This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
- Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.
References
- https://github.com/pjsip/pjproject/security/advisories/GHSA-cv8x-p47p-99wr
- https://github.com/pjsip/pjproject/pull/2716
- https://github.com/pjsip/pjproject/commit/d5f95aa066f878b0aef6a64e60b61e8626e664cd
- https://github.com/pjsip/pjproject/releases/tag/2.11.1
- https://www.debian.org/security/2021/dsa-4999
- https://lists.debian.org/debian-lts-announce/2022/03/msg00035.html
- https://security.gentoo.org/glsa/202210-37