Mozilla Firefox memory corruption

Summaryinfo

A vulnerability classified as critical has been found in Mozilla Firefox. This affects an unknown part. Performing a manipulation results in memory corruption. This vulnerability is reported as CVE-2021-4129. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox (Web Browser) (version now known). It has been classified as critical. This affects some unknown processing. The manipulation with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Mozilla developers and community members Julian Hector, Randell Jesup, Gabriele Svelto, Tyson Smith, Christian Holler, and Masayuki Nakano reported memory safety bugs present in Firefox 94. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 95, Firefox ESR < 91.4.0, and Thunderbird < 91.4.0.

The weakness was disclosed 12/22/2022 by Christian Holler. The advisory is shared at mozilla.org. This vulnerability is uniquely identified as CVE-2021-4129 since 12/16/2021. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 04/16/2025).

The vulnerability scanner Nessus provides a plugin with the ID 208604 (CentOS 7 : thunderbird (RHSA-2021:5046)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability. The upgrade is hosted for download at mozilla.org.

The vulnerability is also documented in the vulnerability database at Tenable (208604). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox

License

• open-source

Website

• Vendor: https://www.mozilla.org/
• Product: https://www.mozilla.org/en-US/firefox/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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