#VU96902 NULL pointer dereference in Certified Asterisk and Asterisk Open Source - CVE-2024-42491

Vulnerability identifier: #VU96902

Vulnerability 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-2024-42491

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Certified Asterisk
Server applications / Conferencing, Collaboration and VoIP solutions
Asterisk Open Source
Server applications / Conferencing, Collaboration and VoIP solutions

Vendor: Digium (Linux Support Services)

Description

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

The vulnerability exists due to a NULL pointer dereference error when handling malformed Contact or Record-Route URI in an incoming SIP request. A remote attacker can send a specially crafted SIP request to the server and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Certified Asterisk: 18.9-cert1 - 18.9-cert11, 20.7-cert1 - 20.7-cert2

Asterisk Open Source: 18.0.0 rc1 - 18.24.2, 19.0.0 rc1 - 19.8.1, 20.0.0 rc1 - 20.0.1, 20.1.0 rc1, 20.1.0 rc2, 20.1.0, 20.2.0 rc1, 20.2.0, 20.2.1, 20.3.0 - 20.3.1, 20.4.0, 20.5.0 - 20.5.2, 20.6.0, 20.7.0, 20.8.0 - 20.8.1, 20.9.0 - 20.9.2, 21.0.0 - 21.0.2, 21.1.0, 21.2.0, 21.3.0 - 21.3.1, 21.4.0 - 21.4.2

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External links
https://github.com/asterisk/asterisk/security/advisories/GHSA-v428-g3cw-7hv9

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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.