Privilege escalation in Asterisk

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU95788

Risk: Medium

CVSSv4.0: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:A/U:Green]

CVE-ID: CVE-2024-42365

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: Yes

Description

The vulnerability allows a remote user to escalate privileges on the system.

The vulnerability exists due to improper access restrictions for users with "write=originate" role. A remote user can alter all configuration files in the `/etc/asterisk/` directory and use a set of built-in features, such as Set+File, Set+Curl, Reload+manager, Reload+pbx_config to overwrite files and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Certified Asterisk: 18.9-cert1 - 20.7-cert1

Asterisk Open Source: 18.0.0 rc1 - 21.4.1

CPE2.3

• cpe:2.3:a:digium_linux_support_services:certified_asterisk:18.9-cert10:*:*:*:*:rv110w_wireless-n_vpn_firewall:*:*
• cpe:2.3:a:digium_linux_support_services:certified_asterisk:20.7-cert1:*:*:*:*:rv110w_wireless-n_vpn_firewall:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:18.24.1:*:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:19.8.1:*:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:20.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:20.1.0:rc1:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:20.1.0:rc2:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:20.1.0:*:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:20.2.0:rc1:*:*:*:*:*:*
• cpe:2.3:a:digium_linux_support_services:asterisk:20.2.0:*:*:*:*:*:*:*

External links

https://github.com/asterisk/asterisk/security/advisories/GHSA-c4cg-9275-6w44
https://github.com/asterisk/asterisk/commit/42a2f4ccfa2c7062a15063e765916b3332e34cc4
https://github.com/asterisk/asterisk/commit/7a0090325bfa9d778a39ae5f7d0a98109e4651c8
https://github.com/asterisk/asterisk/commit/b4063bf756272254b160b6d1bd6e9a3f8e16cc71
https://github.com/asterisk/asterisk/commit/bbe68db10ab8a80c29db383e4dfe14f6eafaf993
https://github.com/asterisk/asterisk/commit/faddd99f2b9408b524e5eb8a01589fe1fa282df2
https://github.com/asterisk/asterisk/blob/14367caaf7241df1eceea7c45c5b261989c2c6db/main/manager.c#L6426
https://github.com/asterisk/asterisk/blob/7d28165cb1b2d02d66e8693bd3fe23ee72fc55d8/main/manager.c#L6426

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. However, a fully functional exploit for this vulnerability is available.