EUVD-2025-17354
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
3Tags
Description
Allegra extractFileFromZip Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Allegra. Authentication is required to exploit this vulnerability. The specific flaw exists within the implementation of the extractFileFromZip method. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-26524.
Analysis
Directory traversal vulnerability in Allegra's extractFileFromZip method that allows authenticated attackers to execute arbitrary code on affected systems. The vulnerability stems from insufficient path validation, enabling remote code execution in the context of the running process. With a CVSS score of 8.8 and requiring only low-privilege authentication, this represents a significant risk to Allegra deployments, though exploitation requires prior authenticated access.
Technical Context
The vulnerability exists in Allegra's file extraction functionality (extractFileFromZip method) and is classified as CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). The root cause is the failure to properly sanitize user-supplied file paths before using them in file operations. An attacker can craft malicious path inputs containing directory traversal sequences (e.g., '../', '..\') to write files outside the intended extraction directory, potentially overwriting critical system files or placing executable code in directories within the application's execution path. This is a classic path traversal vulnerability that escalates to RCE due to the ability to write executable content to accessible locations. The vulnerability was previously tracked as ZDI-CAN-26524 in the Zero Day Initiative database.
Affected Products
The vulnerability affects Allegra installations with the vulnerable extractFileFromZip method implementation. Specific version information, CPE strings, and affected configurations are not provided in the available data. Organizations should consult official Allegra/vendor advisories (e.g., Allegra Security Advisory, ZDI disclosure at https://www.zerodayinitiative.com/) for definitive version ranges. Typical affected scope likely includes: Allegra versions prior to the patch release; all deployment configurations that expose file upload/zip extraction functionality; and installations where file uploads are accessible to authenticated users. CPE format would be: cpe:2.3:a:allegra:allegra:*:*:*:*:*:*:*:* (placeholder; exact vendor and product name from CPE registry needed).
Remediation
Immediate remediation steps: (1) Apply vendor-supplied security patches/updates to Allegra as soon as available from the vendor's security advisory; (2) If patches are not yet available, implement input validation by strictly sanitizing all user-supplied file paths before extraction—reject any path containing directory traversal sequences ('../', '..\', absolute paths, or symbolic links); (3) Enforce file extraction to a restricted sandbox directory with strict permissions; (4) Consider implementing a path canonicalization approach that resolves the final path and verifies it remains within the intended extraction directory; (5) Restrict file upload functionality to authenticated users with minimal privilege where possible; (6) Monitor file system access patterns for suspicious zip extraction activity. Consult vendor advisories at https://www.zerodayinitiative.com/advisories/ZDI-CAN-26524 and official Allegra security updates for patched version numbers and detailed remediation guidance.
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