Description
Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, an authenticated attacker may cause a heap-use-after-free in `PJSIP TCP/SDP` handling by sending a `SIP INVITE` over a connection-oriented transport and disconnecting before Asterisk responds with the `200 OK`. So far, the crash has only been reproduced when Asterisk is built with `Address Sanitizer`, which detects the issue. `Address Sanitizer` is a development tool with significant performance overhead and, according to the maintainer, is not used in production systems. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.
References10
- github.com/asterisk/asterisk/commit/0f076168e0be31ebee37762192d…
- github.com/asterisk/asterisk/commit/27b9544b32f059a4f614169243e…
- github.com/asterisk/asterisk/commit/6e1f4df744369d66ea6f412e355…
- github.com/asterisk/asterisk/commit/9e0386c6d259f0c7499d52499d9…
- github.com/asterisk/asterisk/commit/b7ba85458796ef54b471017287c…
- github.com/asterisk/asterisk/commit/d4e30005940f86942745bcc64f3…
- github.com/asterisk/asterisk/commit/f1e47621472bb3d8ad71f32823f…
- github.com/asterisk/asterisk/releases/tag/20.20.1
- github.com/asterisk/asterisk/releases/tag/21.12.3
- github.com/asterisk/asterisk/releases/tag/22.10.1
Metrics
- CVSS 4.0
-
7.1
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 42 · as of 8 November 2026
- CWE
- CWE-416CWE-664
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.