CVSS 3.1
5.9 mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2023-49786
Medium (5.9). EPSS 5.3% chance of exploitation in the next 30 days.
Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions 18.20.1, 20.5.1, and 21.0.1; as well as certified-asterisk prior to 18.9-cert6; Asterisk is susceptible to a DoS due to a race condition in the hello handshake phase of the DTLS protocol when handling DTLS-SRTP for media setup. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during the attack. Abuse of this vulnerability may lead to a massive Denial of Service on vulnerable Asterisk servers for calls that rely on DTLS-SRTP. Commit d7d7764cb07c8a1872804321302ef93bf62cba05 contains a fix, which is part of versions 18.20.1, 20.5.1, 21.0.1, amd 18.9-cert6.
Severity
- EPSS
- 5.3% chance of exploitation in the next 30 days; higher than 92% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-362, CWE-703
- Published
- Modified
- Record from
- the NVD, synced
Affected
- digium:asterisk
- sangoma:certified_asterisk
References
- http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.html
- http://seclists.org/fulldisclosure/2023/Dec/24
- http://www.openwall.com/lists/oss-security/2023/12/15/7
- https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls-hello-race
- https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05