#VU80809 Out-of-bounds write in Ghostscript - CVE-2020-21890

Vulnerability identifier: #VU80809

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-2020-21890

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ghostscript
Universal components / Libraries / Libraries used by multiple products

Vendor: Artifex Software, Inc.

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error within the clj_media_size() function in devices/gdevclj.c. A remote attacker can trick the victim to open a specially crafted PDF file, trigger an out-of-bounds write and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Ghostscript: 9.10 - 9.50

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External links
https://bugs.ghostscript.com/show_bug.cgi?id=701846
https://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=494eeedf73d13fac5710e56f3a8fb2e7e2379d73

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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.