Privilege escalation via Encode.pm from p5-encode package in Perl

1) Insecure library loading

EUVDB-ID: #VU55804

Risk: Low

CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-36770

CWE-ID: CWE-427 - Uncontrolled Search Path Element

Exploit availability: No

Description

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

The vulnerability exists due to a logic error in the Encode.pm script. A local user can place a malicious library into the current working directory and escalate privileges on the system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Perl: 5.32.0 - 5.35.2

CPE2.3

• cpe:2.3:a:perl:perl:5.32.1:*:*:*:*:*:*:*
• cpe:2.3:a:perl:perl:5.33.9:*:*:*:*:*:*:*
• cpe:2.3:a:perl:perl:5.34.0:*:*:*:*:*:*:*
• cpe:2.3:a:perl:perl:5.35.2:*:*:*:*:*:*:*

External links

https://security-tracker.debian.org/tracker/CVE-2021-36770
https://github.com/Perl/perl5/commit/c1a937fef07c061600a0078f4cb53fe9c2136bb9
https://news.cpanel.com/unscheduled-tsr-10-august-2021/
https://metacpan.org/dist/Encode/changes
https://github.com/dankogai/p5-encode/commit/527e482dc70b035d0df4f8c77a00d81f8d775c74

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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