What’s Vulnerable › Vulnerabilities

CVE-2021-32558

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 9.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-07-30 · updated 2026-06-17
• Weakness: CWE-74

Description

An issue was discovered in Sangoma Asterisk 13.x before 13.38.3, 16.x before 16.19.1, 17.x before 17.9.4, and 18.x before 18.5.1, and Certified Asterisk before 16.8-cert10. If the IAX2 channel driver receives a packet that contains an unsupported media format, a crash can occur.

Affected products

• Debian Linux: 9.0, 11.0
• Digium Asterisk: from 13.0.0 before 13.38.3; from 16.0.0 before 16.19.1; from 17.0.0 before 17.9.4; from 18.0.0 before 18.15.1 — fixed in 13.38.3, 16.19.1, 17.9.4, 18.15.1
• Digium Certified Asterisk: 16.8, 16.8-cert1-rc1, 16.8-cert1-rc2, 16.8-cert1-rc3, 16.8-cert1-rc4, 16.8-cert2 (+11)

How to fix

Upgrade to a fixed version: Digium Asterisk 13.38.3, 16.19.1, 17.9.4, 18.15.1. Check the vendor advisory for mitigations.

References

• http://packetstormsecurity.com/files/163639/Asterisk-Project-Security-Advisory-AST-2021-008.html
• http://seclists.org/fulldisclosure/2021/Jul/49
• https://downloads.asterisk.org/pub/security/AST-2021-008.html
• https://issues.asterisk.org/jira/browse/ASTERISK-29392
• https://lists.debian.org/debian-lts-announce/2021/08/msg00005.html
• https://www.debian.org/security/2021/dsa-4999
• http://packetstormsecurity.com/files/163639/Asterisk-Project-Security-Advisory-AST-2021-008.html
• http://seclists.org/fulldisclosure/2021/Jul/49
• https://downloads.asterisk.org/pub/security/AST-2021-008.html
• https://issues.asterisk.org/jira/browse/ASTERISK-29392
• https://lists.debian.org/debian-lts-announce/2021/08/msg00005.html
• https://www.debian.org/security/2021/dsa-4999

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