CVE-2017-7801 Explained : Impact and Mitigation

A use-after-free vulnerability in Thunderbird, Firefox ESR, and Firefox versions prior to specified versions can lead to exploitable crashes.

Understanding CVE-2017-7801

This CVE involves a use-after-free vulnerability in the "marquee" element during window resizing, affecting Thunderbird, Firefox ESR, and Firefox.

What is CVE-2017-7801?

This vulnerability arises from a freed style object during window resizing, potentially causing a crash that is exploitable.

The Impact of CVE-2017-7801

The vulnerability can lead to a use-after-free issue in the "marquee" element, resulting in exploitable crashes in affected versions of Thunderbird, Firefox ESR, and Firefox.

Technical Details of CVE-2017-7801

This section provides detailed technical information about the vulnerability.

Vulnerability Description

A use-after-free vulnerability occurs during re-computing layout for the "marquee" element while resizing the window, where the updated style object is freed prematurely, leading to exploitable crashes.

Affected Systems and Versions

Thunderbird versions earlier than 52.3
Firefox ESR versions earlier than 52.3
Firefox versions earlier than 55

Exploitation Mechanism

The vulnerability is triggered by the use of a freed style object during window resizing, impacting the "marquee" element.

Mitigation and Prevention

Protecting systems from CVE-2017-7801 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Thunderbird, Firefox ESR, and Firefox to versions 52.3 and 55, respectively.
Monitor vendor advisories for patches and security updates.

Long-Term Security Practices

Regularly update software to the latest versions.
Implement security best practices to prevent similar vulnerabilities.

Patching and Updates

Apply patches provided by Mozilla and other relevant vendors to address the vulnerability.