Asterisk update for pjsip

1) Uncaught Exception

EUVDB-ID: #VU55295

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-32686

CWE-ID: CWE-248 - Uncaught Exception

Exploit availability: No

Description

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

The vulnerability exists due to uncaught exception in pjsip when processing TLS handshake. A remote attacker can initiate TLS connection with the software and then destroy the socket during handshake, causing the application to crash.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Certified Asterisk: 16.8-cert1 - 16.8-cert9

Asterisk Open Source: 13.0.0 - 18.5.0

CPE2.3

• cpe:2.3:a:digium_linux_support_services:certified_asterisk:16.8-cert9:*:*:*:*:rv110w_wireless-n_vpn_firewall:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:13.38.2:*:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:16.19.0:*:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:17.9.3:*:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:18.5.0:*:*:*:*:*:*:*

External links

https://downloads.asterisk.org/pub/security/AST-2021-009.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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