Vulnerability identifier: #VU56530

Vulnerability risk: High

CVSSv3.1: 7.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2021-39863

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Adobe Acrobat
Client/Desktop applications / Office applications
Adobe Reader
Client/Desktop applications / Office applications

Vendor: Adobe

Description

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

The vulnerability exists due to a boundary error when processing PDF files. A remote attacker can trick the victim to open a specially crafted PDF file, trigger heap-based buffer overflow and execute arbitrary code on the target system.

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

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Adobe Acrobat: 17.008.30051 - 17.011.30199, 20.001.30020 - 20.013.20074, 21.001.20135 - 21.005.20148

Adobe Reader: 21.001.20135, 21.001.20149, 21.001.20150, 21.001.20155, 21.005.20054, 21.005.20058, 21.005.20060, 21.005.20148, 2017.008.30051 - 2020.013.20074

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External links
http://helpx.adobe.com/security/products/acrobat/apsb21-55.html

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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. However, proof of concept for this vulnerability is available.