CVE-2023-35942 : Vulnerability Insights and Analysis

This article provides detailed information about CVE-2023-35942, a vulnerability affecting Envoy's gRPC access log functionality.

Understanding CVE-2023-35942

This section covers the impact, technical details, and mitigation strategies related to CVE-2023-35942.

What is CVE-2023-35942?

CVE-2023-35942 is a vulnerability in Envoy's gRPC access log functionality that can lead to a

use-after-free

crash when the listener is drained in specific versions of Envoy.

The Impact of CVE-2023-35942

The vulnerability allows malicious actors to cause a crash, impacting the availability of the affected systems. Successful exploitation could lead to denial of service.

Technical Details of CVE-2023-35942

This section delves into the specifics of the vulnerability, affected systems, and exploitation mechanisms.

Vulnerability Description

Envoy versions prior to 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 are susceptible to a

use-after-free

crash when using gRPC access loggers with a global scope during listener draining.

Affected Systems and Versions

Affected versions include Envoy 1.26.0 to 1.26.3, 1.25.0 to 1.25.8, 1.24.0 to 1.24.9, and versions below 1.23.12.

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating gRPC access log functionality during listener draining, leading to a crash.

Mitigation and Prevention

Learn how to protect your systems and mitigate the impact of CVE-2023-35942.

Immediate Steps to Take

As a workaround, users are advised to disable gRPC access log or halt listener updates to prevent exploitation.

Long-Term Security Practices

Implement secure coding practices, regularly update Envoy to patched versions, and monitor for any unusual activity that could indicate an attack.

Patching and Updates

Ensure your Envoy deployments are always updated to the latest patched versions to protect against known vulnerabilities.