CVE-2022-42705 : What You Need to Know

A critical use-after-free vulnerability has been identified in Sangoma Asterisk versions 16.28, 18.14, 19.6, and certified/18.9-cert2. This vulnerability may allow a remote authenticated attacker to crash Asterisk, leading to a denial of service situation.

Understanding CVE-2022-42705

This section provides an overview of the CVE-2022-42705 vulnerability and its implications.

What is CVE-2022-42705?

The CVE-2022-42705 vulnerability involves a use-after-free issue in res_pjsip_pubsub.c in Sangoma Asterisk, potentially exploited by a remote attacker who is authenticated to the system. The vulnerability can trigger a crash in the Asterisk server, resulting in a denial of service.

The Impact of CVE-2022-42705

If successfully exploited, this vulnerability can lead to a complete system crash, disrupting services and causing downtime for affected Asterisk servers.

Technical Details of CVE-2022-42705

In this section, we delve into the technical aspects of the CVE-2022-42705 vulnerability.

Vulnerability Description

The use-after-free flaw in res_pjsip_pubsub.c allows a remote attacker with authentication privileges to initiate actions on a subscription through a reliable transport. Concurrent activity on the same subscription by the Asterisk server can trigger a crash, resulting in a denial of service.

Affected Systems and Versions

Sangoma Asterisk versions 16.28, 18.14, 19.6, and certified/18.9-cert2 are confirmed to be affected by CVE-2022-42705. Users operating these versions should take immediate action to mitigate the risk.

Exploitation Mechanism

To exploit this vulnerability, an authenticated remote attacker needs to engage in malicious activities on a subscription through a reliable transport while Asterisk is simultaneously performing actions on that same subscription, causing a crash.

Mitigation and Prevention

Protecting your systems from CVE-2022-42705 is crucial to ensure the security and stability of your Sangoma Asterisk deployments.

Immediate Steps to Take

Update to the latest patched version of Sangoma Asterisk to eliminate the vulnerability.
Monitor network traffic for any suspicious activities that may indicate an ongoing exploitation attempt.

Long-Term Security Practices

Implement proper access controls and authentication mechanisms to prevent unauthorized access to the Asterisk server.
Regularly audit and update your Asterisk server to stay protected from known vulnerabilities.

Patching and Updates

Stay informed about security advisories and updates released by Sangoma Asterisk to promptly apply patches that address critical vulnerabilities.