A critical vulnerability has been uncovered in WinZip, designated as CVE-2025-33028, which allows attackers to bypass Windows’ Mark-of-the-Web (MotW) security mechanism. This flaw can lead to the execution of malicious code without user warnings, compromising the security of users relying on this popular file compression tool. The vulnerability, affecting WinZip versions up to 29.0, has raised significant concerns among cybersecurity experts, earning a CVSS score of 7.8. MotW is designed to flag files downloaded from the internet, prompting security warnings about potential dangers. However, WinZip fails to uphold this flag when extracting files from downloaded ZIP archives, leaving users exposed to hidden malware threats.
Exploitation and Security Risks
Security researcher Enis Aksu, who discovered the flaw, highlighted the exploit’s simplicity. Attackers can distribute malicious files through phishing campaigns or compromised websites, and upon extraction with WinZip, these files execute without triggering typical security alerts. This gap in security represents a substantial risk, as it allows unauthorized code execution, privilege escalation, and data theft under the guise of legitimate files. The ease of execution means attackers do not need significant technical expertise, broadening the range of potential threats. This issue also shows an incomplete resolution of a prior issue, CVE-2024-8811, suggesting ongoing challenges in securely handling archive extractions. This vulnerability is not isolated to WinZip alone. Similar flaws have been found in other popular archive utilities like 7-Zip and WinRAR, which faced CVE-2025-0411 and CVE-2025-31334, respectively. WinRAR has already addressed its MotW bypass vulnerability by releasing version 7.11, enhancing its defenses. The repetition of such vulnerabilities across different software emphasizes the need for rigorous and ongoing security evaluations of these utilities to prevent attackers from exploiting similar flaws in the future.
Mitigation Strategies and Recommendations
Currently, no patch is available for the discovered WinZip vulnerability, necessitating several mitigation strategies for users and enterprises to consider. Users should be cautious when opening archives from unknown or untrusted sources. Using alternative archive utilities that correctly handle the MotW flag can also provide an additional layer of security. Additionally, it is important to scan all extracted files with updated antivirus software before opening them to identify and neutralize any potential threats.
For organizations, administrators should implement stringent controls to monitor and manage the execution of newly extracted files within corporate environments. Disabling the automatic execution of macros in Office applications can prevent potentially malicious macro-laden documents from executing. This layered approach to security helps mitigate the risks associated with this vulnerability and enhances overall defenses against various malware threats.
The Importance of Robust Security Measures
The discovery of the WinZip vulnerability underscores the critical importance of having robust security measures in place, even during routine file operations. It emphasizes the need for a defense-in-depth approach to cybersecurity, where multiple layers of defenses work together to protect against potential threats. As attackers continue to exploit weaknesses in software, it is essential for users and organizations to remain vigilant, routinely update their software, and adhere to best practices in cybersecurity.
The persistent nature of vulnerabilities in archive utilities highlights the necessity for both users and developers to prioritize security in their digital practices. Continuous education on emerging threats and diligent adherence to security protocols can significantly reduce the risks posed by such vulnerabilities.
Conclusion and Future Considerations
A significant security flaw has been identified in WinZip, classified under the code CVE-2025-33028. This vulnerability enables attackers to bypass Windows’ Mark-of-the-Web (MotW) security mechanism, allowing the execution of harmful code without warning the user. This flaw compromises the safety of users who depend on WinZip, a widely-used file compression utility. The issue affects all WinZip versions up to 29.0 and has alarmed cybersecurity specialists, reflected by its CVSS score of 7.8. Windows’ MotW feature is meant to mark files downloaded from the internet, issuing security alerts about potential risks. Unfortunately, WinZip does not retain this critical flag when extracting files from ZIP archives, exposing users to concealed malware threats. This shortcoming leaves a gap in the intended security protocols, which can be exploited by cybercriminals to execute malicious activities without being detected. Immediate action and updates from WinZip developers are necessary to safeguard users and to reinforce cybersecurity measures against such vulnerabilities.