#VU20411 OS Command Injection in GNU patch - CVE-2018-20969

Vulnerability identifier: #VU20411

Vulnerability risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2018-20969

CWE-ID: CWE-78

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
GNU patch
Operating systems & Components / Operating system package or component

Vendor: GNU

Description

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to the "do_ed_script" function in the "pch.c" file does not block strings beginning with a ! character. A remote unauthenticated attacker can trick a victim to open a specially crafted patch file and execute arbitrary OS shell commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

GNU patch: 2.1 - 2.7.6

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External links
https://git.savannah.gnu.org/cgit/patch.git/commit/?id=3fcd042d26d70856e826a42b5f93dc4854d80bf0

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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