Mozilla Firefox/Firefox ESR/Thunderbird Sandbox input validation

Summaryinfo

A vulnerability identified as critical has been detected in Mozilla Firefox, Firefox ESR and Thunderbird. The affected element is an unknown function of the component Sandbox. The manipulation leads to input validation. This vulnerability is documented as CVE-2019-9812. The attack can be initiated remotely. There is not any 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) and classified as critical. This issue affects some unknown functionality of the component Sandbox. The manipulation with an unknown input leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Given a compromised sandboxed content process due to a separate vulnerability, it is possible to escape that sandbox by loading accounts.firefox.com in that process and forcing a log-in to a malicious Firefox Sync account. Preference settings that disable the sandbox are then synchronized to the local machine and the compromised browser would restart without the sandbox if a crash is triggered. This vulnerability affects Firefox ESR < 60.9, Firefox ESR < 68.1, and Firefox < 69.

The weakness was released 01/08/2020 as Bug 1538008 as not defined bug report (Bugzilla). It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2019-9812 since 03/14/2019. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/26/2025).

Upgrading eliminates this vulnerability.

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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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