CVE-2021-46837: Null Pointer Dereference
respjsipt38 in Sangoma Asterisk 16.x before 16.16.2, 17.x before 17.9.3, and 18.x before 18.2.2, and Certified Asterisk before 16.8-cert7, allows an attacker to trigger a crash by sending an m=image line and zero port in a response to a T.38 re-invite initiated by Asterisk. This is a re-occurrence of the CVE-2019-15297 symptoms but not for exactly the same reason. The crash occurs because there is an append operation relative to the active topology, but this should instead be a replace operation.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2021-46837?
The severity of CVE-2021-46837 is medium with a severity value of 6.5.
How does CVE-2021-46837 affect Sangoma Asterisk?
CVE-2021-46837 affects Sangoma Asterisk versions 16.x before 16.16.2, 17.x before 17.9.3, and 18.x before 18.2.2, and Certified Asterisk before 16.8-cert7.
How can an attacker trigger a crash with CVE-2021-46837?
An attacker can trigger a crash with CVE-2021-46837 by sending an m=image line and zero port in a response to a T.38 re-invite initiated by Asterisk.
What is the remedy for CVE-2021-46837?
The remedy for CVE-2021-46837 is to update to Sangoma Asterisk version 16.16.2, 17.9.3, 18.2.2, or Certified Asterisk version 16.8-cert7.
Where can I find more information about CVE-2021-46837?
More information about CVE-2021-46837 can be found at the following references: https://downloads.asterisk.org/pub/security/AST-2021-006.html, https://security-tracker.debian.org/tracker/CVE-2021-46837, https://security-tracker.debian.org/tracker/CVE-2019-15297