CVE-2023-49786
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…
Does this matter?
Lower severity and a low EPSS score (5.29%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 5.29% probability · 93th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-703, CWE-362
- Affected
- digium/asterisk · sangoma/certified asterisk
- Source
- security-advisories@github.com
EPSS 5.3% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2023/Dec/24Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/15/7Exploit, Mailing List
- https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls-hello-raceExploit
- https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05Patch
- https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pqExploit, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/12/msg00019.html
- http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2023/Dec/24Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/15/7Exploit, Mailing List
- https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls-hello-raceExploit
- https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05Patch
- https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pqExploit, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2023/12/msg00019.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.