#VU50535 Out-of-bounds read in Adobe Acrobat and Adobe Reader - CVE-2021-21042

Vulnerability identifier: #VU50535

Vulnerability risk: Medium

CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2021-21042

CWE-ID: CWE-125

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 gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger out-of-bounds read error and read contents of memory on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Adobe Acrobat: 15.006.30306 - 15.006.30527, 17.008.30051 - 17.012.20098, 18.009.20044, 18.009.20050, 18.011.20035, 18.011.20038, 18.011.20040, 18.011.20055, 18.011.20058, 18.011.20063, 19.008.20071, 19.008.20080, 19.008.20081, 19.010.20064, 19.010.20069, 19.010.20091, 19.010.20098, 19.010.20100, 19.012.20034, 19.012.20035, 19.012.20036, 19.012.20040, 19.021.20047, 19.021.20056, 19.021.20058, 19.021.20061, 20.001.30002 - 20.013.20074

Adobe Reader: 2015.006.30306 - 2020.013.20074

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External links
https://helpx.adobe.com/security/products/acrobat/apsb21-09.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.