CVE-2023-34448 : Security Advisory and Response

A vulnerability has been discovered in Grav, a flat-file content management system. This CVE, identified as CVE-2023-34448, exposes a Server-side Template Injection (SSTI) risk via Twig Default Filters.

Understanding CVE-2023-34448

This section delves into the details of the CVE-2023-34448 vulnerability.

What is CVE-2023-34448?

CVE-2023-34448 affects Grav versions prior to 1.7.42 and arises due to a server-side template injection leveraging the default

filter()

function. The vulnerability allows attackers to invoke arbitrary unsafe functions, leading to potential remote code execution.

The Impact of CVE-2023-34448

The impact of this vulnerability is rated as HIGH in terms of confidentiality, integrity, and availability, with a base severity score of 8.8, highlighting its critical nature.

Technical Details of CVE-2023-34448

This section provides more technical insights into CVE-2023-34448.

Vulnerability Description

The vulnerability stems from the patch for the previous CVE-2022-2073 not adequately blocking Twig's Core Extension built-in functions that could be exploited for unsafe operations. The absence of proper validation allows for the execution of malicious code.

Affected Systems and Versions

Grav versions below 1.7.42 are confirmed to be impacted by this vulnerability, exposing systems to potential attacks.

Exploitation Mechanism

Attackers can exploit this vulnerability by leveraging the exposed Twig

map()

and

reduce()

filter functions to execute arbitrary code remotely.

Mitigation and Prevention

In response to CVE-2023-34448, consider the following proactive measures.

Immediate Steps to Take

Update Grav to version 1.7.42 or above to mitigate this vulnerability.
Implement strict input validation mechanisms to prevent SSTI attacks.

Long-Term Security Practices

Regularly monitor security advisories and updates from Grav to stay informed about emerging threats.
Conduct security audits and penetration testing to identify and remediate vulnerabilities proactively.

Patching and Updates

Apply patches released by Grav promptly to address known vulnerabilities and enhance system security.