CVE-2021-32781 Explained : Impact and Mitigation
Discover details of CVE-2021-32781 affecting Envoy versions >= 1.16.0 and < 1.19.1. Learn about the impact, technical aspects, and mitigation steps for this high severity vulnerability.
A vulnerability (CVE-2021-32781) has been identified in Envoy affecting versions >= 1.16.0 and < 1.19.1. This vulnerability allows an attacker to cause a Denial of Service (DoS) by sending a specially crafted request, resulting in access to a freed memory block. It is recommended to apply the provided fixes to address this issue and disable specific extensions as a temporary workaround.
Understanding CVE-2021-32781
This section provides detailed insights into the CVE-2021-32781 vulnerability affecting the Envoy proxy.
What is CVE-2021-32781?
CVE-2021-32781 involves continued processing of requests after a locally generated response, leading to memory access issues that could be exploited by malicious actors.
The Impact of CVE-2021-32781
The vulnerability poses a high severity risk with a CVSS base score of 8.6, allowing unauthenticated attackers to trigger a DoS condition on affected systems.
Technical Details of CVE-2021-32781
Explore the technical aspects of CVE-2021-32781 to understand the vulnerability better.
Vulnerability Description
In affected versions of Envoy, the incomplete termination of request processing after a local response can be exploited to access freed memory blocks, potentially resulting in a DoS condition.
Affected Systems and Versions
Envoy versions >= 1.16.0 and < 1.19.1 are impacted by this vulnerability, requiring immediate attention to prevent exploitation.
Exploitation Mechanism
Attackers can exploit this vulnerability by sending specifically crafted requests, leveraging extensions that modify request or response bodies to trigger a DoS condition.
Mitigation and Prevention
Learn how to mitigate the risks associated with CVE-2021-32781 and prevent potential exploitation.
Immediate Steps to Take
Apply the latest fixes provided by Envoy to address the vulnerability and consider disabling specific extensions known to increase the size of request or response bodies.
Long-Term Security Practices
Implement robust security measures, conduct regular vulnerability assessments, and keep systems updated to prevent similar vulnerabilities in the future.
Patching and Updates
Stay informed about security updates released by Envoy, ensuring that systems are promptly patched to mitigate the risk of CVE-2021-32781.