Vulnerability · Published Feb 18, 2021 · Assigned by mitre

CVE-2020-35776

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 4.1% (higher than 91% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)6.5Medium

Exploit odds (30 days)4.1%top 9.3% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

A buffer overflow in res_pjsip_diversion.c in Sangoma Asterisk versions 13.38.1, 16.15.1, 17.9.1, and 18.1.1 allows remote attacker to crash Asterisk by deliberately misusing SIP 181 responses.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.20	asterisk	18.1.1-r0	ALPINE-CVE-2020-35776
Alpine:v3.21	asterisk	18.1.1-r0	ALPINE-CVE-2020-35776
Alpine:v3.22	asterisk	18.1.1-r0	ALPINE-CVE-2020-35776
Alpine:v3.23	asterisk	18.1.1-r0	ALPINE-CVE-2020-35776
Alpine:v3.24	asterisk	18.1.1-r0	ALPINE-CVE-2020-35776
Debian:14	asterisk	1:16.16.1~dfsg-1	DEBIAN-CVE-2020-35776
Ubuntu:22.04:LTS	asterisk	no fix listed	UBUNTU-CVE-2020-35776
Ubuntu:24.04:LTS	asterisk	no fix listed	UBUNTU-CVE-2020-35776
Ubuntu:25.10	asterisk	no fix listed	UBUNTU-CVE-2020-35776
Ubuntu:26.04:LTS	asterisk	no fix listed	UBUNTU-CVE-2020-35776
Ubuntu:26.10	asterisk	no fix listed	UBUNTU-CVE-2020-35776

Affected products (as reported)

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

References

https://issues.asterisk.org/ x_refsource_MISC
20210218 AST-2021-001: Remote crash in res_pjsip_diversion mailing-list, x_refsource_FULLDISC
https://downloads.asterisk.org/pub/security/AST-2021-001.html x_refsource_CONFIRM
https://issues.asterisk.org/jira/browse/ASTERISK-29227 x_refsource_CONFIRM
http://packetstormsecurity.com/files/161470/Asterisk-Project-Security-Advisory-AST-2021-001.html x_refsource_MISC