Vulnerability · Published Feb 18, 2021 · Assigned by mitre

CVE-2021-26712

High 7.5

In plain English

A high-severity security flaw in the asterisk package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 3.6% (higher than 90% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.5High

Exploit odds (30 days)3.6%top 10.4% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

Incorrect access controls in res_srtp.c in Sangoma Asterisk 13.38.1, 16.16.0, 17.9.1, and 18.2.0 and Certified Asterisk 16.8-cert5 allow a remote unauthenticated attacker to prematurely terminate secure calls by replaying SRTP packets.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.20	asterisk	18.2.1-r0	ALPINE-CVE-2021-26712
Alpine:v3.21	asterisk	18.2.1-r0	ALPINE-CVE-2021-26712
Alpine:v3.22	asterisk	18.2.1-r0	ALPINE-CVE-2021-26712
Alpine:v3.23	asterisk	18.2.1-r0	ALPINE-CVE-2021-26712
Alpine:v3.24	asterisk	18.2.1-r0	ALPINE-CVE-2021-26712
Ubuntu:22.04:LTS	asterisk	no fix listed	UBUNTU-CVE-2021-26712
Ubuntu:24.04:LTS	asterisk	no fix listed	UBUNTU-CVE-2021-26712
Ubuntu:25.10	asterisk	no fix listed	UBUNTU-CVE-2021-26712
Ubuntu:26.04:LTS	asterisk	no fix listed	UBUNTU-CVE-2021-26712
Ubuntu:26.10	asterisk	no fix listed	UBUNTU-CVE-2021-26712

Affected products (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

References

https://downloads.asterisk.org/pub/security/ x_refsource_MISC
20210218 AST-2021-003: Remote attacker could prematurely tear down SRTP calls mailing-list, x_refsource_FULLDISC
https://downloads.asterisk.org/pub/security/AST-2021-003.html x_refsource_CONFIRM
https://issues.asterisk.org/jira/browse/ASTERISK-29260 x_refsource_CONFIRM
http://packetstormsecurity.com/files/161473/Asterisk-Project-Security-Advisory-AST-2021-003.html x_refsource_MISC