Vulnerability · Published Feb 19, 2021 · Assigned by mitre
CVE-2021-26713
Medium 6.5
In plain English
A medium-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 1.9% (higher than 79% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)6.5Medium
Exploit odds (30 days)1.9%top 20.6% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | asterisk | 18.2.1-r0 | ALPINE-CVE-2021-26713 |
| Alpine:v3.21 | asterisk | 18.2.1-r0 | ALPINE-CVE-2021-26713 |
| Alpine:v3.22 | asterisk | 18.2.1-r0 | ALPINE-CVE-2021-26713 |
| Alpine:v3.23 | asterisk | 18.2.1-r0 | ALPINE-CVE-2021-26713 |
| Alpine:v3.24 | asterisk | 18.2.1-r0 | ALPINE-CVE-2021-26713 |
| Ubuntu:22.04:LTS | asterisk | no fix listed | UBUNTU-CVE-2021-26713 |
| Ubuntu:24.04:LTS | asterisk | no fix listed | UBUNTU-CVE-2021-26713 |
| Ubuntu:25.10 | asterisk | no fix listed | UBUNTU-CVE-2021-26713 |
| Ubuntu:26.04:LTS | asterisk | no fix listed | UBUNTU-CVE-2021-26713 |
| Ubuntu:26.10 | asterisk | no fix listed | UBUNTU-CVE-2021-26713 |
Affected products (as reported)
References
- https://downloads.asterisk.org/pub/security/ x_refsource_MISC
- https://downloads.asterisk.org/pub/security/AST-2021-004.html x_refsource_MISC
- https://issues.asterisk.org/jira/browse/ASTERISK-29205 x_refsource_MISC