CVE-2023-49786

High

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.

SeverityHigh
CVSS7.5
Exploit probability—
ProductDigium Asterisk
PublishedDec 14, 2023
First seenDec 14, 2023
Weakness typeCWE-703CWE-703

How to fix

Update
  • digium asterisk18.20.1, 20.5.1 or later

Affected products

ProductAffected versionsFixed in
digium asteriskv < 18.20.1, 19.0.0 ≤ v < 20.5.1, 21.0.018.20.1, 20.5.1
sangoma certified_asterisk13.13.0, 16.8.0, 18.9—

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