#VU69827 Use-after-free in Asterisk Open Source and Certified Asterisk - CVE-2022-42705

Vulnerability identifier: #VU69827

Vulnerability risk: Low

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:Clear]

CVE-ID: CVE-2022-42705

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

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

Vendor: Digium (Linux Support Services)

Description

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

The vulnerability exists due to a use-after-free error within res_pjsip_pubsub.c, res_pjsip_outbound_registration.c, pjsip_transport_events.c files when performing activity on a subscription via a reliable transport at the same time Asterisk is also performing activty on that subscription. A remote user can trigger a use-after-free error and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Asterisk Open Source: 16.0.0 rc1 - 16.29.0, 17.0.0 rc1 - 17.9.4, 18.0.0 rc1 - 18.15.0, 19.0.0 rc1 - 19.7.0, 20.0.0 rc1 - 20.0.0

Certified Asterisk: 16.3-cert1 - 18.9-cert2

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External links
https://downloads.asterisk.org/pub/security/AST-2022-008.html

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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.