Condorlab

Asterisk – Vulnerability in Sangoma Asterisk 13.x, 16.x, and 17.x.


Advisory IDRSN-SIP-1653



Vulnerability Information

An issue was discovered in channels/chan_sip.c in Sangoma Asterisk 13.x, 16.x, and 17.x, and Certified Asterisk 13.21, because of an incomplete fix for CVE-2019-18351.


Technical Information

A SIP request can be sent to Asterisk that can change a SIP peer’s IP address. A REGISTER does not need to occur, and calls can be hijacked as a result. The only thing that needs to be known is the peer’s name; authentication details such as passwords do not need to be known. This vulnerability is only exploitable when the nat option is set to the default, or auto_force_rport.


Solutions

The UCTM solution from RedShift Networks provides the industry’s first complete security solution developed to secure VOIP networks, endpoints and applications. His research team Condor-Labs.com is constantly looking for new attack patterns, advanced penetration testing methods, vulnerability identification and deployment of new signatures for constantly subscribed clients. For more information visit www.redshiftnetworks.com


External Resources

https://kb.juniper.net/JSA10953https://www.juniper.net/documentation/en_US/junos/topics/topic-map/security-sip-alg.htmlhttps://www.juniper.net/documentation/en_US/junos/topics/topic-map/security-sip-alg.html

https://www.asterisk.org/downloads/security-advisories
https://lists.debian.org/debian-lts-announce/2019/11/msg00038.html

Common Vulnerabilities and Exposures (CVE)

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-18790