Vulnerability identifier: #VU10855

Vulnerability risk: Low

CVSSv3.1: 3.5 [CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-18206

CWE-ID: CWE-120

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
zsh
Client/Desktop applications / Software for system administration

Vendor: SourceForge

Description
The vulnerability allows a local attacker to cause DoS condition on the target system.

The weakness exists in the utils.c source code file due to insufficient checks on buffer lengths for symlink expansion. A local attacker can send specially crafted input, trigger memory corruption and cause the service to crash.

Mitigation
Update to version 5.4.

Vulnerable software versions

zsh: 5.0.0 - 5.3.1

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External links
http://sourceforge.net/p/zsh/code/ci/c7a9cf465dd620ef48d586026944d9bd7a0d5d6d/

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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.