CVE-2023-30847 : Vulnerability Insights and Analysis

H2O vulnerable to read from uninitialized pointer in the reverse proxy handler

Understanding CVE-2023-30847

This CVE-2023-30847 affects H2O, an HTTP server, in versions 2.3.0-beta2 and prior. The vulnerability arises when the reverse proxy handler attempts to process a specific type of invalid HTTP request, leading to potential security risks.

What is CVE-2023-30847?

H2O, in vulnerable versions, reads from an uninitialized pointer when the reverse proxy handler processes certain invalid HTTP requests. This can result in crashes or the inadvertent leakage of sensitive information to backend HTTP servers.

The Impact of CVE-2023-30847

The impact of CVE-2023-30847 is considered high, with a CVSS base score of 8.2. This vulnerability can potentially impact the availability of the system, making it susceptible to crashes and information leakage.

Technical Details of CVE-2023-30847

In affected versions of H2O, the reverse proxy handler's incorrect processing of specific invalid HTTP requests triggers the vulnerability by reading from an uninitialized pointer. The issue has been addressed in pull request number 3229, which has been merged into the

master

branch in commit f010336.

Vulnerability Description

The vulnerability in H2O arises from its reverse proxy handler attempting to build an upstream URL by reading from an uninitialized pointer when processing certain invalid HTTP requests.

Affected Systems and Versions

H2O versions equal to or below 2.3.0-beta2 are impacted by this vulnerability.

Exploitation Mechanism

Exploiting this vulnerability involves crafting and sending a specific type of invalid HTTP request to trigger the reverse proxy handler to read from the uninitialized pointer.

Mitigation and Prevention

To address CVE-2023-30847, users of H2O are strongly advised to take immediate action to secure their systems and prevent exploitation.

Immediate Steps to Take

Users should upgrade to commit f010336 or a later version to mitigate the vulnerability effectively.

Long-Term Security Practices

Implementing regular software updates and patches is crucial to stay protected from known vulnerabilities like CVE-2023-30847.

Patching and Updates

Users should ensure that their H2O servers are regularly updated with the latest patches and security fixes to prevent exploitation of this vulnerability.