CVE-2019-18836 Explained : Impact and Mitigation

Envoy 1.12.0 has a vulnerability that allows a remote denial of service due to resource loops, potentially leading to worker thread occupation.

Understanding CVE-2019-18836

This CVE involves a vulnerability in Envoy version 1.12.0 that can be exploited to cause a denial of service attack.

What is CVE-2019-18836?

The vulnerability in Envoy 1.12.0 enables a remote attacker to trigger a denial of service by creating resource loops, causing a single idle TCP connection to occupy a worker thread indefinitely.

The Impact of CVE-2019-18836

The vulnerability poses a risk of resource exhaustion and can disrupt the normal operation of affected systems, potentially leading to service unavailability.

Technical Details of CVE-2019-18836

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The vulnerability in Envoy 1.12.0 allows a single idle TCP connection to keep a worker thread in an infinite busy loop when utilizing the continue_on_listener_filters_timeout feature.

Affected Systems and Versions

Affected Version: 1.12.0 of Envoy

Exploitation Mechanism

The vulnerability can be exploited remotely by creating resource loops, leading to the occupation of worker threads and potential denial of service.

Mitigation and Prevention

Protecting systems from CVE-2019-18836 requires immediate actions and long-term security measures.

Immediate Steps to Take

Upgrade Envoy to a patched version that addresses the vulnerability.
Monitor network traffic for any suspicious activity that could indicate exploitation attempts.

Long-Term Security Practices

Regularly update and patch software to mitigate known vulnerabilities.
Implement network segmentation to limit the impact of potential attacks.

Patching and Updates

Stay informed about security advisories and updates from Envoy to apply patches promptly.