CVE-2020-28327 — MEDIUM (5.3)

Q: How severe is CVE-2020-28327?

CVE-2020-28327 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2020-28327?

Check the references section above for vendor advisories and patch information. Affected products include: Digium Certified Asterisk, Sangoma Asterisk.

Vulnerability 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.

CVSS Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Digium	Certified Asterisk	16.8
Sangoma	Asterisk	>= 13.0.0, < 13.37.1

Related Weaknesses (CWE)

CWE-404

References

http://downloads.asterisk.org/pub/security/AST-2020-001.htmlPatchVendor Advisory
https://issues.asterisk.org/jira/browse/ASTERISK-29057ExploitIssue TrackingVendor Advisory
http://downloads.asterisk.org/pub/security/AST-2020-001.htmlPatchVendor Advisory
https://issues.asterisk.org/jira/browse/ASTERISK-29057ExploitIssue TrackingVendor Advisory

FAQ

What is CVE-2020-28327?

CVE-2020-28327 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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 re...

How severe is CVE-2020-28327?

CVE-2020-28327 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2020-28327?

Check the references section above for vendor advisories and patch information. Affected products include: Digium Certified Asterisk, Sangoma Asterisk.