CVE-2023-49786
mediumpriority · track · 26EPSS 0.053 · 93 %ileDEEURUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.4–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (27)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2023-3158Digium Certified Asterisk: Mehrere SchwachstellenDeutsch2023-12-14csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Digium Certified Asterisk und Asterisk ausnutzen, um einen Denial of Service Angriff durchzuführen oder Informationen offenzulegen.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (20)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2023-49786/cnnvd
- https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls-hello-racecnnvd
- https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05cnnvd
- https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pqcnnvd
- https://www.auscert.org.au/bulletins/ESB-2024.0005cnnvd
- https://www.auscert.org.au/bulletins/ESB-2024.0105cnnvd
- http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.htmlenisa_euvd
- http://seclists.org/fulldisclosure/2023/Dec/24enisa_euvd
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