#VU53925 Use-after-free in Adobe Reader and Adobe Acrobat - CVE-2021-28632

Vulnerability identifier: #VU53925

Vulnerability risk: High

CVSSv4.0: 5.7 [CVSS:4.0/AV:L/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-2021-28632

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

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

Vendor: Adobe

Description

The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to a boundary condition when processing AcroForm fields. A remote attacker can create a specially crafted PDF file, trick the victim into opening it, trigger a use-after-free error and compromise the affected system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Adobe Reader: 21.001.20135, 21.001.20149, 21.001.20150, 21.001.20155, 2017.011.30156 - 2020.013.20074

Adobe Acrobat: 17.008.30051 - 17.011.30196, 20.001.30020 - 20.013.20074, 21.001.20135 - 21.001.20155

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External links
https://helpx.adobe.com/security/products/acrobat/apsb21-37.html
https://www.zerodayinitiative.com/advisories/ZDI-21-663/

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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.