Is CVE-2020-28327 actively exploited?

No active exploitation of CVE-2020-28327 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2020-28327 be exploited remotely?

Yes. CVE-2020-28327 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2020-28327?

CVE-2020-28327 has a CVSS score of 5.3 (MEDIUM).

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MEDIUM

CVE-2020-28327

CWE-404Published: November 6, 2020· Updated: Jun 17, 2026

5.3

CVSS v3.1

Official Description

A res_pjsip_session crash was discovered in Asterisk Open Source 13.x before 13.37.1, 16.x before 16.14.1, 17.x before 17.8.1, and 18.x before 18.0.1. and Certified Asterisk before 16.8-cert5. Upon receiving a new SIP Invite, Asterisk did not return the created dialog locked or referenced. This caused a gap between the creation of the dialog object, and its next use by the thread that created it. Depending on some off-nominal circumstances and timing, it was possible for another thread to free said dialog in this gap. Asterisk could then crash when the dialog object, or any of its dependent objects, were dereferenced or accessed next by the initial-creation thread. Note, however, that this crash can only occur when using a connection-oriented protocol (e.g., TCP or TLS, but not UDP) for SIP transport. Also, the remote client must be authenticated, or Asterisk must be configured for anonymous calling.

NVD Source

Technical Analysis

CVE-2020-28327 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.3.