CVE-2021-26906 : An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.

An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.

Published 2021-02-18 20:15:13

Updated 2021-02-24 17:03:16

Source MITRE

View at NVD, CVE.org

Products affected by CVE-2021-26906

Digium » Asterisk
Versions from including (>=) 13.0.0 and before (<) 13.38.2
cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
Matching versions
Digium » Asterisk
Versions from including (>=) 18.0 and before (<) 18.2.1
cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
Matching versions
Digium » Asterisk
Versions from including (>=) 16.0.0 and before (<) 16.16.1
cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
Matching versions
Digium » Asterisk
Versions from including (>=) 17.0.0 and before (<) 17.9.2
cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8
cpe:2.3:a:digium:certified_asterisk:16.8:-:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert1-rc1
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc1:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert1-rc2
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc2:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert1-rc3
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc3:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert1-rc4
cpe:2.3:a:digium:certified_asterisk:16.8:cert1-rc4:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert2
cpe:2.3:a:digium:certified_asterisk:16.8:cert2:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert3
cpe:2.3:a:digium:certified_asterisk:16.8:cert3:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert4
cpe:2.3:a:digium:certified_asterisk:16.8:cert4:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert4-rc1
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc1:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert4-rc2
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc2:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert4-rc3
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc3:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert4-rc4
cpe:2.3:a:digium:certified_asterisk:16.8:cert4-rc4:*:*:*:*:*:*
Matching versions
Digium » Certified Asterisk » Version: 16.8 Update Cert5
cpe:2.3:a:digium:certified_asterisk:16.8:cert5:*:*:*:*:*:*
Matching versions

Threat overview for CVE-2021-26906

Top countries where our scanners detected CVE-2021-26906

Top open port discovered on systems with this issue 80

IPs affected by CVE-2021-26906 27,763

Threat actors abusing to this issue? Yes

Find out if you^* are affected by CVE-2021-26906!

^*Directly or indirectly through your vendors, service providers and 3rd parties. Powered by attack surface intelligence from SecurityScorecard.

Exploit prediction scoring system (EPSS) score for CVE-2021-26906

EPSS FAQ

0.19%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 57 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2021-26906

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
4.3	MEDIUM	AV:N/AC:M/Au:N/C:N/I:N/A:P	8.6	2.9	NIST
Access Vector: Network Access Complexity: Medium Authentication: None Confidentiality Impact: None Integrity Impact: None Availability Impact: Partial
5.9	MEDIUM	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H	2.2	3.6	NIST
Attack Vector: Network Attack Complexity: High Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: None Availability: High

CWE ids for CVE-2021-26906

CWE-404 Improper Resource Shutdown or Release

The product does not release or incorrectly releases a resource before it is made available for re-use.

Assigned by: nvd@nist.gov (Primary)

References for CVE-2021-26906

https://downloads.asterisk.org/pub/security/AST-2021-005.html

AST-2021-005
Vendor Advisory
http://seclists.org/fulldisclosure/2021/Feb/61

Full Disclosure: AST-2021-005: Remote Crash Vulnerability in PJSIP channel driver
Mailing List;Patch;Third Party Advisory
http://packetstormsecurity.com/files/161477/Asterisk-Project-Security-Advisory-AST-2021-005.html

Asterisk Project Security Advisory - AST-2021-005 ≈ Packet Storm
Third Party Advisory
https://downloads.asterisk.org/pub/security/

Index of /pub/security
Vendor Advisory

CVEs referencing this url
https://issues.asterisk.org/jira/browse/ASTERISK-29196

[ASTERISK-29196] res_pjsip: Segmentation fault - Digium/Asterisk JIRA
Issue Tracking;Patch;Vendor Advisory