#VU50963 Input validation error - CVE-2020-35652

Vulnerability identifier: #VU50963

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-35652

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Description

The vulnerability allows a remote authenticated user to perform a denial of service (DoS) attack.

An issue was discovered in res_pjsip_diversion.c in Sangoma Asterisk before 13.38.0, 14.x through 16.x before 16.15.0, 17.x before 17.9.0, and 18.x before 18.1.0. A crash can occur when a SIP message is received with a History-Info header that contains a tel-uri, or when a SIP 181 response is received that contains a tel-uri in the Diversion header.

Mitigation
Install update from vendor's website.

External links
https://downloads.asterisk.org/pub/security/AST-2020-003.html
https://downloads.asterisk.org/pub/security/AST-2020-004.html
https://issues.asterisk.org/jira/browse/ASTERISK-29191
https://issues.asterisk.org/jira/browse/ASTERISK-29219

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.