CVE-2020-11100 : What You Need to Know

A vulnerability in the HPACK decoder in HAProxy versions before 2.1.4 could allow a remote attacker to execute arbitrary code.

Understanding CVE-2020-11100

This CVE involves a security issue in the HPACK decoder of HAProxy versions prior to 2.1.4.

What is CVE-2020-11100?

In the hpack_dht_insert function in hpack-tbl.c, a remote attacker can manipulate a crafted HTTP/2 request to write arbitrary bytes around a specific heap location, potentially leading to remote code execution.

The Impact of CVE-2020-11100

The vulnerability could be exploited by a remote attacker to execute arbitrary code on the target system, posing a significant security risk.

Technical Details of CVE-2020-11100

This section delves into the technical aspects of the CVE.

Vulnerability Description

The vulnerability exists in the HPACK decoder in HAProxy versions 1.8 through 2.x before 2.1.4, allowing an attacker to manipulate heap memory.

Affected Systems and Versions

HAProxy versions 1.8 through 2.x before 2.1.4 are impacted by this vulnerability.

Exploitation Mechanism

By sending a specially crafted HTTP/2 request, an attacker can exploit the vulnerability to write arbitrary bytes around a specific heap location, potentially leading to remote code execution.

Mitigation and Prevention

Protecting systems from CVE-2020-11100 requires immediate action and long-term security measures.

Immediate Steps to Take

Update HAProxy to version 2.1.4 or newer to mitigate the vulnerability.
Monitor network traffic for any suspicious activity that could indicate exploitation.

Long-Term Security Practices

Regularly update software and apply security patches promptly to prevent known vulnerabilities.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

Stay informed about security advisories and updates from HAProxy to address vulnerabilities promptly.