#VU51573 Out-of-bounds read in Adobe Acrobat and Adobe Reader - CVE-2021-21089

Vulnerability identifier: #VU51573

Vulnerability risk: Medium

CVSSv4.0: 1.7 [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:U/U:Green]

CVE-ID: CVE-2021-21089

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

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 within the handling of URIs by weblink.api. 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
https://www.zerodayinitiative.com/advisories/ZDI-21-336/

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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.