CVE-2023-49786: Asterisk susceptible to Denial of Service via DTLS Hello packets during call initiation
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.
Affected Software
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Event History
Frequently Asked Questions
What is the severity of CVE-2023-49786?
CVE-2023-49786 is classified as a denial of service (DoS) vulnerability due to a race condition.
How do I fix CVE-2023-49786?
To fix CVE-2023-49786, upgrade Asterisk to version 18.20.1, 20.5.1, 21.0.1, or the compatible certified-asterisk version 18.9-cert6 or later.
What versions are affected by CVE-2023-49786?
CVE-2023-49786 affects Asterisk versions prior to 18.20.1, 20.5.1, 21.0.1, and certified-asterisk versions before 18.9-cert6.
What component in Asterisk is impacted by CVE-2023-49786?
CVE-2023-49786 impacts the DTLS handshake phase in Asterisk, leading to a potential DoS condition.
Is CVE-2023-49786 easy to exploit?
Given that it is a denial of service vulnerability resulting from a race condition, exploitation may require specific conditions during the DTLS handshake.