CVE-2021-23953 : Security Advisory and Response

A detailed overview of CVE-2021-23953, impacting various Mozilla products due to cross-origin information leakage vulnerability.

Understanding CVE-2021-23953

This CVE, affecting Firefox, Thunderbird, and Firefox ESR, allows for cross-origin information leakage when specific crafted PDF files are accessed.

What is CVE-2021-23953?

The vulnerability in Mozilla products allows a specially crafted PDF to confuse the PDF reader, resulting in the leakage of cross-origin information.

The Impact of CVE-2021-23953

If exploited, this vulnerability could lead to the exposure of sensitive information when chunked data is accessed through the PDF reader.

Technical Details of CVE-2021-23953

An insight into the vulnerability, affected systems, and the exploitation mechanism.

Vulnerability Description

Clicking into a malicious PDF could cause the PDF reader to leak cross-origin information, affecting Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

Affected Systems and Versions

Mozilla products susceptible to this vulnerability include Firefox, Thunderbird, and Firefox ESR, with versions below Firefox 85, Thunderbird 78.7, and Firefox ESR 78.7.

Exploitation Mechanism

Exploitation occurs when users access specially crafted PDF files, triggering the PDF reader to disclose cross-origin information.

Mitigation and Prevention

Preventive measures and steps to secure systems against CVE-2021-23953.

Immediate Steps to Take

Users should avoid accessing untrusted PDF files and implement security updates promptly to mitigate the risk of information leakage.

Long-Term Security Practices

Regularly update Mozilla products to patched versions, maintain secure browsing habits, and stay informed about security advisories.

Patching and Updates

Apply security patches provided by Mozilla to address the CVE-2021-23953 vulnerability and enhance system security.