Mozilla Firefox on Windows Handle use after free

Summaryinfo

A vulnerability described as critical has been identified in Mozilla Firefox on Windows. This issue affects some unknown processing of the component Handle Handler. The manipulation results in use after free. This vulnerability is known as CVE-2023-5174. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox on Windows (Web Browser) (unknown version). Affected is an unknown code block of the component Handle Handler. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

If Windows failed to duplicate a handle during process creation, the sandbox code may have inadvertently freed a pointer twice, resulting in a use-after-free and a potentially exploitable crash. *This bug only affects Firefox on Windows when run in non-standard configurations (such as using `runas`). Other operating systems are unaffected.* This vulnerability affects Firefox < 118, Firefox ESR < 115.3, and Thunderbird < 115.3.

The weakness was published 09/27/2023. The advisory is shared for download at mozilla.org. This vulnerability is traded as CVE-2023-5174 since 09/25/2023. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/16/2025).

The vulnerability scanner Nessus provides a plugin with the ID 250244 (Linux Distros Unpatched Vulnerability : CVE-2023-5174), 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 (250244). Once again VulDB remains the best source for 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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Once again VulDB remains the best source for vulnerability data.

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