CVE-2024-30370 in WinRAR
Summary
by MITRE • 04/03/2024
RARLAB WinRAR Mark-Of-The-Web Bypass Vulnerability. This vulnerability allows remote attackers to bypass the Mark-Of-The-Web protection mechanism on affected installations of RARLAB WinRAR. User interaction is required to exploit this vulnerability in that the target must perform a specific action on a malicious page. The specific flaw exists within the archive extraction functionality. A crafted archive entry can cause the creation of an arbitrary file without the Mark-Of-The-Web. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the current user. Was ZDI-CAN-23156.
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Analysis
by VulDB Data Team • 04/09/2025
The CVE-2024-30370 vulnerability represents a critical security flaw in RARLAB WinRAR that undermines the Mark-Of-The-Web (MOTW) protection mechanism designed to prevent potentially malicious files from executing on Windows systems. This vulnerability falls under the CWE-120 category of Buffer Overflow and specifically targets the archive extraction functionality within WinRAR's processing pipeline. The MOTW is a Windows security feature that places a zone identifier on files downloaded from the internet, which triggers security warnings and restricts execution of potentially harmful content. When this protection is bypassed, users may unknowingly execute malicious code that would otherwise be blocked by the operating system's security controls.
The technical exploitation of this vulnerability occurs through crafted archive entries that manipulate WinRAR's extraction process to create arbitrary files without proper MOTW tagging. This flaw exploits the archive extraction functionality by leveraging the way WinRAR handles file paths and metadata during decompression operations. Attackers can craft malicious RAR archives that contain specially formatted entries designed to bypass the MOTW enforcement mechanism, allowing them to place executable files in locations where they would normally be restricted. The vulnerability requires user interaction to be effective, meaning that a user must actively open or extract a malicious archive for the attack to succeed. This user interaction requirement makes the attack vector more targeted but also more potentially effective since users may be less cautious when performing legitimate archive operations.
The operational impact of this vulnerability extends beyond simple file creation, as it provides attackers with a pathway to execute arbitrary code within the context of the current user's privileges. This represents a significant escalation from the initial bypass, as it enables attackers to perform malicious activities such as installing backdoors, stealing credentials, or conducting further reconnaissance. The vulnerability's relationship to the ZDI-CAN-23156 identifier indicates it was independently discovered and documented, highlighting the widespread concern about WinRAR's security posture. This type of vulnerability directly aligns with ATT&CK technique T1059.001 for command and script interpreter and T1068 for exploit for privilege escalation, as attackers can leverage the bypassed protections to execute malicious payloads with elevated system access.
Security professionals should implement multiple layers of defense to mitigate this vulnerability, including immediate patching of affected WinRAR installations and implementing network-based restrictions on archive file types. Organizations should also consider deploying application control solutions that can prevent the execution of untrusted archives from potentially malicious sources. The vulnerability demonstrates the importance of proper input validation and the need for security controls to be implemented at multiple layers of the attack chain. Additionally, user education regarding the risks of extracting archives from untrusted sources remains critical, as the requirement for user interaction means that social engineering elements may be necessary to achieve successful exploitation. This vulnerability underscores the ongoing challenges in securing archive processing utilities and the need for regular security assessments of commonly used software components that handle untrusted data inputs.