CVE-2021-26713

moderate-risk

Published 2021-02-19

A stack-based buffer overflow in res_rtp_asterisk.c in Sangoma Asterisk before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6 allows an authenticated WebRTC client to cause an Asterisk crash by sending multiple hold/unhold requests in quick succession. This is caused by a signedness comparison mismatch.

Do I need to act?

0.21% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 6.5/10 Medium

NETWORK / LOW complexity

Affected Products (14)

Asterisk

Certified Asterisk

Affected Vendors

Digium

References (6)

Vendor Advisory https://downloads.asterisk.org/pub/security/

Vendor Advisory https://downloads.asterisk.org/pub/security/AST-2021-004.html

Vendor Advisory https://issues.asterisk.org/jira/browse/ASTERISK-29205

Vendor Advisory https://downloads.asterisk.org/pub/security/

Vendor Advisory https://downloads.asterisk.org/pub/security/AST-2021-004.html

Vendor Advisory https://issues.asterisk.org/jira/browse/ASTERISK-29205

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moderate-risk

Severity 24/34 · High

Exploitability 1/34 · Minimal

Exposure 18/34 · Moderate