CVE-2025-46652 is a medium-severity vulnerability affecting IZArc, a popular archive extraction utility. The vulnerability is classified under CWE-830, which involves the inclusion of web functionality from an untrusted source. Specifically, this issue arises due to a Mark-of-the-Web (MotW) bypass during the extraction process. MotW is a security feature in Windows that tags files downloaded from the internet or other untrusted sources, triggering security warnings or restrictions when those files are opened. In IZArc versions up to 4.5, when a user extracts files from an archive that carries the MotW attribute, the extracted files do not inherit this security tag. This failure to propagate the MotW attribute effectively removes the security boundary that Windows enforces on potentially unsafe files, allowing extracted files to be treated as if they originated from a trusted source. The vulnerability requires user interaction, specifically the extraction of an archive file containing MotW. The CVSS 3.1 base score is 6.1 (medium), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), scope changed (S:C), low confidentiality and integrity impact (C:L/I:L), and no availability impact (A:N). Although no known exploits are currently reported in the wild, the vulnerability could be leveraged by attackers to bypass Windows security warnings, potentially facilitating the execution of malicious payloads or social engineering attacks that rely on users trusting extracted files. The scope change indicates that the vulnerability affects resources beyond the initially vulnerable component, meaning that the extracted files could be used in a broader attack context.

For European organizations, this vulnerability poses a moderate risk primarily in environments where IZArc is used for handling archive files, especially those received from external or untrusted sources such as email attachments or downloads. The MotW bypass can lead to users inadvertently executing malicious files without Windows security prompts, increasing the risk of malware infections, data breaches, or lateral movement within networks. This is particularly concerning for sectors with high reliance on file exchange and archiving, such as finance, manufacturing, and government agencies. The integrity and confidentiality of data could be compromised if attackers exploit this flaw to deliver payloads that modify or exfiltrate sensitive information. Although availability impact is not indicated, the indirect consequences of malware infections could lead to service disruptions. The requirement for user interaction limits automated exploitation but does not eliminate risk, as social engineering tactics can induce users to extract malicious archives. Organizations with strict security policies and endpoint protection may mitigate some risk, but those with legacy systems or less controlled environments remain vulnerable.

To mitigate this vulnerability effectively, European organizations should: 1) Immediately review and restrict the use of IZArc, especially versions up to 4.5, replacing it with archive utilities that correctly propagate MotW attributes or have verified security postures. 2) Implement strict policies to scan all archive files with advanced endpoint detection and response (EDR) tools before extraction, focusing on files originating from untrusted sources. 3) Educate users about the risks of extracting archives from unknown or suspicious origins, emphasizing the importance of verifying file sources even if no Windows security warnings appear. 4) Employ application whitelisting and execution control policies to prevent unauthorized execution of files extracted from archives, regardless of MotW status. 5) Monitor network and endpoint logs for unusual extraction activities or execution of files immediately following archive extraction. 6) Coordinate with IZArc vendor or community to obtain patches or updates addressing this vulnerability and apply them promptly once available. 7) Consider sandboxing or isolated environments for handling archives from external sources to contain potential threats. These steps go beyond generic advice by focusing on controlling the extraction environment, user behavior, and leveraging layered security controls specific to the nature of this MotW bypass.