Mozilla Firefox/Firefox ESR/Thunderbird out-of-bounds write

Summaryinfo

A vulnerability identified as critical has been detected in Mozilla Firefox, Firefox ESR and Thunderbird. This affects an unknown part. This manipulation causes out-of-bounds write. The identification of this vulnerability is CVE-2020-15659. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox, Firefox ESR and Thunderbird (Web Browser) (affected version not known). It has been declared as critical. Affected by this vulnerability is some unknown functionality. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Mozilla developers and community members reported memory safety bugs present in Firefox 78 and Firefox ESR 78.0. 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 < 79, Firefox ESR < 68.11, Firefox ESR < 78.1, Thunderbird < 68.11, and Thunderbird < 78.1.

The weakness was shared 08/10/2020 as Bug 1550133 as not defined bug report (Bugzilla). The advisory is shared at bugzilla.mozilla.org. This vulnerability is known as CVE-2020-15659 since 07/10/2020. The attack can be launched remotely. The exploitation doesn't need any form of authentication. 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 $0-$5k at the moment (estimation calculated on 08/09/2025).

The vulnerability scanner Nessus provides a plugin with the ID 246408 (Linux Distros Unpatched Vulnerability : CVE-2020-15659), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (246408). The entries VDB-159468, VDB-159467, VDB-159466 and VDB-159465 are related to this item. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox
• Firefox ESR
• Thunderbird

License

• open-source

Website

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

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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