#VU54156 Out-of-bounds read in Mozilla Firefox - CVE-2021-29968

Vulnerability identifier: #VU54156

Vulnerability risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-29968

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition when drawing text onto a canvas with WebRender disabled. A remote attacker can create a specially crafted web page, trick the victim into opening it, trigger out-of-bounds read error and read contents of memory on the system.

Note, the vulnerability affects Windows installations only.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 80.0 - 89.0

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2021-27/

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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.