CVE-2022-31793 : Security Advisory and Response

A vulnerability with CVE-2022-31793 has been identified in the muhttpd software before version 1.1.7. This vulnerability allows remote attackers to read arbitrary files by manipulating a URL constructed with a single character before the intended path in the filesystem. This issue arises from the code skipping over the initial character when serving files, impacting various Arris router models.

Understanding CVE-2022-31793

This section delves into the details of the CVE-2022-31793 vulnerability.

What is CVE-2022-31793?

The CVE-2022-31793 vulnerability exists in the do_request function in the request.c file of muhttpd versions prior to 1.1.7. It enables malicious actors to access sensitive files by crafting a URL with a specific format to bypass file serving restrictions, thus compromising the security of affected systems.

The Impact of CVE-2022-31793

The vulnerability poses a significant risk to devices utilizing muhttpd versions before 1.1.7, particularly impacting Arris NVG443, NVG599, NVG589, and NVG510 devices, as well as Arris-derived BGW210 and BGW320 devices. By exploiting this flaw, threat actors can potentially access confidential information stored on the filesystem.

Technical Details of CVE-2022-31793

This section elaborates on the technical aspects of CVE-2022-31793.

Vulnerability Description

The vulnerability in muhttpd arises from the inadequate handling of URLs, allowing attackers to access arbitrary files on the system by manipulating the URL structure. This flaw can be leveraged to extract sensitive data from the affected devices.

Affected Systems and Versions

Devices running muhttpd versions preceding 1.1.7 are vulnerable to CVE-2022-31793. Specifically, Arris NVG443, NVG599, NVG589, NVG510, BGW210, and BGW320 devices are confirmed to be affected by this security issue.

Exploitation Mechanism

Malicious actors can exploit this vulnerability by crafting a URL that contains a single character positioned before the desired file path, tricking the code into skipping the initial character and granting unauthorized access to files stored on the system.

Mitigation and Prevention

This section outlines the necessary steps to mitigate the risks associated with CVE-2022-31793.

Immediate Steps to Take

To address this vulnerability, it is crucial to update muhttpd to version 1.1.7 or newer to prevent remote attackers from exploiting this security loophole. Additionally, implementing firewall rules and network segmentation can help reduce the attack surface and fortify the system's security posture.

Long-Term Security Practices

In the long term, organizations should conduct regular security assessments, including vulnerability scans and penetration testing, to identify and remediate potential security gaps proactively. Moreover, educating users about safe browsing practices and ensuring timely software updates can enhance the overall security resilience of the IT infrastructure.

Patching and Updates

Applying patches released by the software vendor is imperative to safeguard systems against known vulnerabilities. Organizations should establish a robust patch management process to deploy updates promptly and minimize the window of exposure to security threats.