Multiple Asterisk Products CVE-2019-18790 Authorization Bypass Vulnerability

Description

Multiple Asterisk Products are prone to an authorization-bypass vulnerability. An attacker can exploit this issue to bypass certain security restrictions and perform unauthorized actions; this may aid in launching further attacks. The following products are affected: Versions prior to Asterisk Open Source 13.29.2, 16.6.2 and 17.0.1 Versions prior to Certified Asterisk 13.21-cert5

Technologies Affected

• Asterisk Certified Asterisk 13.21
• Asterisk Certified Asterisk 13.21-cert
• Asterisk Certified Asterisk 13.21-cert1
• Asterisk Certified Asterisk 13.21-cert2
• Asterisk Certified Asterisk 13.21-cert3
• Asterisk Certified Asterisk 13.21-cert4
• Asterisk Open Source 13.0
• Asterisk Open Source 13.1.0
• Asterisk Open Source 13.10.0
• Asterisk Open Source 13.11.0
• Asterisk Open Source 13.12.0
• Asterisk Open Source 13.13.0
• Asterisk Open Source 13.13.1
• Asterisk Open Source 13.14.0
• Asterisk Open Source 13.14.1
• Asterisk Open Source 13.15.0
• Asterisk Open Source 13.16.0
• Asterisk Open Source 13.17.0
• Asterisk Open Source 13.17.1
• Asterisk Open Source 13.18.0
• Asterisk Open Source 13.18.1
• Asterisk Open Source 13.18.2
• Asterisk Open Source 13.18.3
• Asterisk Open Source 13.18.4
• Asterisk Open Source 13.18.5
• Asterisk Open Source 13.19.0
• Asterisk Open Source 13.19.2
• Asterisk Open Source 13.2.0
• Asterisk Open Source 13.20.0
• Asterisk Open Source 13.21.0
• Asterisk Open Source 13.21.1
• Asterisk Open Source 13.22.0
• Asterisk Open Source 13.23.0
• Asterisk Open Source 13.23.1
• Asterisk Open Source 13.24.0
• Asterisk Open Source 13.25.0
• Asterisk Open Source 13.26.0
• Asterisk Open Source 13.27.0
• Asterisk Open Source 13.27.1
• Asterisk Open Source 13.28.0
• Asterisk Open Source 13.28.1
• Asterisk Open Source 13.3.0
• Asterisk Open Source 13.4.0
• Asterisk Open Source 13.5.0
• Asterisk Open Source 13.6.0
• Asterisk Open Source 13.7.0
• Asterisk Open Source 13.8.0
• Asterisk Open Source 13.9.0
• Asterisk Open Source 16.0
• Asterisk Open Source 16.0.0
• Asterisk Open Source 16.0.1
• Asterisk Open Source 16.1.0
• Asterisk Open Source 16.2.0
• Asterisk Open Source 16.2.1
• Asterisk Open Source 16.3.0
• Asterisk Open Source 16.4.0
• Asterisk Open Source 16.4.1
• Asterisk Open Source 16.5.0
• Asterisk Open Source 16.5.1
• Asterisk Open Source 16.6.0
• Asterisk Open Source 16.6.1
• Asterisk Open Source 17.0.0

Recommendations

Block external access at the network boundary, unless external parties require service.
If global access isn’t needed, filter access to the affected computer at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of successful exploits.

Run all software as a nonprivileged user with minimal access rights.
To limit the potential damage that a successful exploit may achieve, run all nonadministrative software as a regular user with the least amount of privileges required to successfully operate.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of suspicious or anomalous activity. This may help detect malicious actions that an attacker may take after successfully exploiting vulnerabilities in applications. Review all applicable logs regularly.

Updates are available. Please see the references or vendor advisory for more information.