Vulnerability identifier: #VU69827

Vulnerability risk: Low

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

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: 20.0.0 - 20.0.0 rc2, 19.0.0 rc1 - 19.7.0 rc2, 18.0.0 rc1 - 18.15.0 rc2, 16.0.0 - 16.29.0 rc2, 17.0.0 - 17.9.4

Certified Asterisk: 16.3-cert1 - 18.9-cert2

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External links
http://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.