CVE-2021-36773 : Security Advisory and Response
Learn about CVE-2021-36773, a vulnerability in uBlock Origin and nMatrix allowing denial of service attacks by exploiting parameter nesting. Find out impacted versions and mitigation steps.
uBlock Origin before 1.36.2 and nMatrix before 4.4.9 support an arbitrary depth of parameter nesting for strict blocking, which allows crafted web sites to cause a denial of service (unbounded recursion that can trigger memory consumption and a loss of all blocking functionality).
Understanding CVE-2021-36773
This CVE focuses on the vulnerability found in uBlock Origin and nMatrix versions prior to specific releases.
What is CVE-2021-36773?
The vulnerability in uBlock Origin and nMatrix allows malicious websites to exploit an arbitrary depth of parameter nesting, leading to a denial of service by triggering memory consumption and disrupting blocking functionality.
The Impact of CVE-2021-36773
Crafted web pages can use this vulnerability to execute unbounded recursion, impacting system memory and compromising the blocking capabilities of affected versions.
Technical Details of CVE-2021-36773
The following details shed light on the technical aspects of this CVE.
Vulnerability Description
The flaw lies in the unlimited parameter nesting capability of uBlock Origin and nMatrix, enabling a DoS attack that hampers the normal functionality of these applications.
Affected Systems and Versions
Versions of uBlock Origin before 1.36.2 and nMatrix before 4.4.9 are susceptible to this vulnerability.
Exploitation Mechanism
Crafted websites utilize the unrestricted parameter nesting feature to initiate a denial of service attack, causing a significant strain on system memory and disrupting blocking functionalities.
Mitigation and Prevention
To address and prevent exploitation of CVE-2021-36773, consider the following measures.
Immediate Steps to Take
Users should update uBlock Origin to version 1.36.2 or later, and nMatrix to version 4.4.9 or above to mitigate the risk of this vulnerability.
Long-Term Security Practices
Regularly update security software and employ best practices to enhance the overall security posture of systems and devices.
Patching and Updates
Stay informed about security patches and updates released by the respective vendors to ensure protection against known vulnerabilities.