CVE-2021-28682 : Vulnerability Insights and Analysis

An integer overflow vulnerability has been identified in Envoy through version 1.71.1. This flaw allows remote attackers to exploit a very large grpc-timeout value, leading to unexpected timeout calculations.

Understanding CVE-2021-28682

This CVE describes a critical security issue in the Envoy proxy server software that could be abused by malicious actors to disrupt service availability.

What is CVE-2021-28682?

CVE-2021-28682 is a remotely exploitable integer overflow vulnerability found in Envoy versions up to 1.71.1. The flaw arises from improper handling of overly large grpc-timeout values, resulting in erroneous timeout calculations that could be leveraged by attackers.

The Impact of CVE-2021-28682

The impact of this vulnerability is severe, as it enables threat actors to manipulate timeout calculations, potentially leading to service disruptions or denial of service attacks.

Technical Details of CVE-2021-28682

This section delves into the specifics of the vulnerability, including affected systems, exploitation mechanisms, and potential risks associated with the issue.

Vulnerability Description

The vulnerability in Envoy through version 1.71.1 resides in an integer overflow related to processing grpc-timeout values, allowing attackers to trigger unexpected timeout behaviors.

Affected Systems and Versions

Envoy versions up to 1.71.1 are affected by CVE-2021-28682. Users of these versions are urged to take immediate action to mitigate the risk posed by this vulnerability.

Exploitation Mechanism

Malicious actors can exploit this vulnerability by submitting excessively large grpc-timeout values, causing the server to miscalculate timeouts and potentially disrupt service availability.

Mitigation and Prevention

To safeguard systems from potential exploitation of CVE-2021-28682, immediate steps should be taken to address the issue and prevent unauthorized access.

Immediate Steps to Take

Upon discovery of this vulnerability, users are advised to update Envoy to a patched version or apply relevant security fixes to mitigate the risk of exploitation.

Long-Term Security Practices

Implementing robust security measures, performing regular security assessments, and staying updated on security advisories are essential for maintaining system integrity and resilience.

Patching and Updates

Regularly applying security patches and updates provided by Envoy is crucial to ensure that systems are protected against known vulnerabilities and security threats.