CVE-2025-33028 in WinZip
Summary
by MITRE • 04/15/2025
In WinZip through 29.0, there is a Mark-of-the-Web Bypass Vulnerability because of an incomplete fix for CVE-2024-8811. This vulnerability allows attackers to bypass the Mark-of-the-Web protection mechanism on affected installations of WinZip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of archived files. When extracting files from a crafted archive that bears the Mark-of-the-Web, WinZip does not propagate the Mark-of-the-Web to the extracted files. An attacker can leverage this vulnerability to execute arbitrary code in the context of the current user.
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Analysis
by VulDB Data Team • 05/26/2025
The vulnerability identified as CVE-2025-33028 represents a critical security flaw in WinZip versions up to 29.0 that undermines the operating system's built-in protection mechanism known as Mark-of-the-Web. This protection is designed to prevent users from inadvertently executing potentially malicious code downloaded from the internet by marking files with a security attribute that prevents automatic execution. The vulnerability stems from an incomplete remediation of a previous issue, CVE-2024-8811, which demonstrates the challenges organizations face when addressing security patches that require complex interactions between multiple system components. The flaw specifically manifests in the file extraction process where WinZip fails to properly propagate the Mark-of-the-Web attribute from archived files to their extracted counterparts, effectively nullifying the security protections that should be in place.
The technical implementation of this vulnerability occurs during the archive extraction process where WinZip processes files that have been marked with the Mark-of-the-Web attribute but fails to maintain this security context when creating the extracted files on the local filesystem. This bypass mechanism operates at the file system level where the security attributes that normally prevent execution of downloaded content are stripped away during the extraction process. The vulnerability requires user interaction to be exploited, meaning that an attacker must convince a user to visit a malicious webpage or open a specially crafted archive file containing malicious payloads. This user interaction requirement aligns with common attack vectors in the cybersecurity landscape and represents a social engineering component that makes the vulnerability particularly dangerous in real-world scenarios. The underlying flaw can be categorized under CWE-284 Access Control Issues, specifically related to improper handling of file system permissions and security attributes.
The operational impact of this vulnerability extends beyond simple file extraction and represents a significant threat to user security and system integrity. When an attacker successfully exploits this vulnerability, they can execute arbitrary code in the context of the currently logged-in user, potentially leading to complete system compromise depending on the user's privileges. This execution context is particularly dangerous because it allows attackers to bypass multiple layers of security controls that would normally prevent malicious code from running. The vulnerability creates a persistent threat vector where malicious code can be delivered through seemingly benign archive files that are downloaded from untrusted sources, making it difficult for users to distinguish between legitimate and malicious content. From an attack lifecycle perspective, this vulnerability maps to the execution phase in the MITRE ATT&CK framework, where attackers leverage system weaknesses to run malicious code. The impact is amplified because the vulnerability affects a commonly used utility like WinZip, which many users trust for handling compressed files, making successful exploitation more likely and harder to detect.
Mitigation strategies for this vulnerability should focus on both immediate remediation and long-term security practices. The most direct solution involves updating to a patched version of WinZip that properly implements the Mark-of-the-Web attribute propagation mechanism. Organizations should implement comprehensive patch management procedures to ensure all systems are updated promptly when security patches become available. Additionally, users should be educated about the risks associated with opening archive files from untrusted sources and should be trained to recognize potentially malicious content. Network-level defenses including web filtering and sandboxing mechanisms can provide additional protection layers to prevent users from accessing malicious content that could exploit this vulnerability. Security monitoring should include detection of unusual file extraction activities and potential attempts to bypass security controls. The vulnerability also highlights the importance of proper security testing for software utilities that interact with user-controlled data, particularly in areas where security attributes and access controls are involved. Organizations should consider implementing application whitelisting policies to restrict execution of potentially malicious code and maintain regular security assessments to identify similar incomplete fixes that may exist in other software components.