CVE-2023-49786 Asterisk susceptible to Denial of Service via DTLS Hello packets during call initiation
Attackers can cause a Denial of Service on Asterisk servers by exploiting a race condition in DTLS-SRTP handshakes, blocking new encrypted calls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-49786?
CVE-2023-49786 is a high-severity vulnerability in Digium Asterisk, published on 14 Dec 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2023-49786?
It affects 2 products.
Products include Digium Asterisk, Sangoma Certified Asterisk.
How do I fix CVE-2023-49786?
Upgrade to a fixed version.
Is CVE-2023-49786 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-49786 exists.
Other vulnerabilities in Digium Asterisk
Sources
Also known as ALPINE-CVE-2023-49786, DEBIAN-CVE-2023-49786, GHSA-hxj9-xwr8-w8pq, UBUNTU-CVE-2023-49786.