CVE-2021-46837 Information

Description

res_pjsip_t38 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.

Reference

https://downloads.asterisk.org/pub/security/AST-2021-006.html