CVE-2025-0411 7-Zip Mark of the Web Bypass Vulnerability

CVE-2025-0411 is a significant security vulnerability identified in versions of the 7-Zip file archiver prior to 24.09. This flaw allows attackers to bypass the Mark-of-the-Web (MoTW) protection mechanism in Windows. MoTW is a security feature that flags files downloaded from untrusted sources, prompting caution before execution. The vulnerability arises because 7-Zip fails to propagate the MoTW to files extracted from specially crafted archives, potentially enabling the execution of malicious code without user warnings.

What is Vulnerable to CVE-2025-0411

All versions of 7-Zip released before version 24.09 are susceptible to this vulnerability. Users who have not updated their 7-Zip software since November 2024 are at risk. The vulnerability is particularly concerning for Windows users, as the MoTW bypass can lead to the execution of malicious files without the typical security prompts.

Mitigation and Remediation for CVE-2025-0411

To protect systems from potential exploitation of CVE-2025-0411, users should take the following steps:

• Update 7-Zip: Download and install version 24.09 or later from the official 7-Zip website.

• Exercise Caution with Untrusted Files: Avoid opening files from unknown or suspicious sources, especially compressed archives.

• Leverage Security Features: Ensure that your operating system and security software are configured to detect and block malicious files.

By implementing these measures, users can significantly reduce the risk of exploitation.

Impact of Successful Exploitation of CVE-2025-0411

If exploited, CVE-2025-0411 allows attackers to execute arbitrary code on the affected system with the privileges of the current user. This can lead to unauthorized access, data theft, and potential system compromise. Notably, this vulnerability has been actively exploited in the wild. Attackers have used spear-phishing campaigns with malicious 7-Zip archives to deliver malware, such as SmokeLoader, to Ukrainian organizations.

Proof of Concept for CVE-2025-0411

A proof-of-concept (PoC) exploit for CVE-2025-0411 has been publicly released. The PoC demonstrates how an attacker can create a double-compressed 7-Zip archive that, when extracted, bypasses the MoTW protection, allowing for the execution of malicious code without user warnings. This PoC underscores the critical nature of the vulnerability and the importance of applying patches promptly.

For a detailed analysis and demonstration of the PoC, refer to the GitHub repository by security researcher dhmosfunk.

By staying informed and proactive, users and organizations can mitigate the risks associated with CVE-2025-0411 and enhance their overall cybersecurity posture.