#VU34 Default set-uid root for perl_startup script - CVE-2016-1531

Vulnerability identifier: #VU34

Vulnerability risk: Low

CVSSv4.0: 7.3 [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:A/U:Clear]

CVE-ID: CVE-2016-1531

CWE-ID: CWE-250

Exploitation vector: Local

Exploit availability: Yes

Description

The vulnerability allows a local user to obtain elevated privileges.

The vulnerability exists due to improper default permission for "perl_startup" startup script, which has set-uid root bit. A local user can obtain root privileges on the system.

Successful exploitation of this vulnerability will allow the local attacker to obtain elevated privileges and execute arbitrary commands as root.

Mitigation
Install the latest version Exim 4.84.2, 4.85.2 or 4.86.2.

External links
https://lists.exim.org/lurker/message/20160302.191005.a72d8433.en.html

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