CVE-2023-49786

moderate-risk
Published 2023-12-14

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.

Do I need to act?

-
0.10% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.5/10 High
NETWORK / LOW complexity

Affected Products (20)

Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk
Certified Asterisk

Affected Vendors

Digium Sangoma

References (14)

Exploit http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.ht...
Exploit http://seclists.org/fulldisclosure/2023/Dec/24
Exploit http://www.openwall.com/lists/oss-security/2023/12/15/7
Exploit https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls...
Patch https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62c...
Exploit https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pq
https://lists.debian.org/debian-lts-announce/2023/12/msg00019.html
Exploit http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.ht...
Exploit http://seclists.org/fulldisclosure/2023/Dec/24
Exploit http://www.openwall.com/lists/oss-security/2023/12/15/7
Exploit https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls...
Patch https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62c...
Exploit https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pq
https://lists.debian.org/debian-lts-announce/2023/12/msg00019.html
48
/ 100
moderate-risk
Severity 26/34 · High
Exploitability 0/34 · Minimal
Exposure 22/34 · High