CVE-2020-28327 : Vulnerability Insights and Analysis

A res_pjsip_session crash was discovered in Asterisk Open Source versions before 13.37.1, 16.14.1, 17.8.1, and 18.0.1, and Certified Asterisk before 16.8-cert5. This vulnerability could lead to a crash under specific circumstances.

Understanding CVE-2020-28327

This CVE identifies a critical vulnerability in Asterisk Open Source versions that could result in a crash when certain conditions are met.

What is CVE-2020-28327?

The vulnerability in Asterisk Open Source versions could allow a crash to occur when handling a new SIP Invite, specifically when using a connection-oriented protocol for SIP transport.

The Impact of CVE-2020-28327

The vulnerability could lead to a crash in Asterisk under specific conditions, potentially affecting the availability and stability of the affected systems.

Technical Details of CVE-2020-28327

This section provides more technical insights into the vulnerability.

Vulnerability Description

A gap in the creation and usage of dialog objects in Asterisk could lead to crashes when certain threads attempt to access or dereference these objects.

Affected Systems and Versions

Asterisk Open Source versions before 13.37.1, 16.14.1, 17.8.1, and 18.0.1
Certified Asterisk before 16.8-cert5

Exploitation Mechanism

Crash occurs when using a connection-oriented protocol for SIP transport
Remote client must be authenticated or Asterisk configured for anonymous calling

Mitigation and Prevention

Protecting systems from this vulnerability is crucial to maintaining security.

Immediate Steps to Take

Update Asterisk to versions 13.37.1, 16.14.1, 17.8.1, 18.0.1, or Certified Asterisk 16.8-cert5
Monitor for any unusual system behavior that could indicate exploitation

Long-Term Security Practices

Regularly update and patch Asterisk to the latest versions
Implement network segmentation and access controls to limit exposure

Patching and Updates

Apply patches provided by Asterisk to address the vulnerability