Privilege escalation in zsh

1) Buffer overflow

EUVDB-ID: #VU11349

Risk: Low

CVSSv3.1: 7.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-1083

CWE-ID: CWE-120 - Buffer overflow

Exploit availability: No

Description

The vulnerability allows a local attacker to gain elevated privileges on the target system.

The weakness exists in the compctl.c source code file due to insufficient bounds checking on the PATH_MAX-sized buffer used for file completion candidates. A local attacker can create a malicious directory path, trick the victim into using the autocomplete functionality to traverse the path, trigger buffer overflow and execute arbitrary code with root privileges.

Successful exploitation of the vulnerability may result in system compromise.

Mitigation

Update to version 5.4.2-test-1.

Vulnerable software versions

zsh: 3.0.0 - 5.4.1

External links

http://sourceforge.net/p/zsh/code/ci/259ac472eac291c8c103c7a0d8a4eaf3c2942ed7

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.