CVE-2025-14602 in vsDesk
Summary
by MITRE • 08/20/2026
The application generates uploaded file names using a weak and predictable method based on the request timestamp. This allows a remote attacker to accurately guess or brute-force the generated filename within a short time window. An attacker can successfully locate and access uploaded files, which can be used to facilitate further attacks.
Apply patch from vendor https://vsdesk.ru/ . Versions 14.0101 and on have the patch.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability described constitutes a critical insecure random number generation flaw within the file upload mechanism of the application, specifically identified by its reliance on predictable identifiers derived from request timestamps. In secure software design, filenames for uploaded content must be generated using cryptographically strong pseudo-random number generators to ensure uniqueness and unpredictability. However, in this instance, the system utilizes a weak method based on the current time at which the HTTP request is processed. This approach fails to provide sufficient entropy, as the timestamp represents a highly constrained search space that an attacker can easily enumerate or predict with high accuracy. The core technical flaw lies in the lack of randomness and uniqueness guarantees when creating file names, which directly violates fundamental security principles regarding resource identification and access control.
From an operational perspective, this weakness allows remote attackers to perform directory traversal-like attacks through filename guessing rather than traditional path manipulation. By knowing or approximating the time at which a victim uploaded a file, an attacker can systematically iterate through potential filenames within that narrow temporal window. Once the correct filename is identified, the attacker gains direct access to the stored content without needing valid authentication credentials for those specific files. This capability transforms what might otherwise be a simple storage issue into a significant data exposure risk, as sensitive documents, images, or configuration files can be retrieved by any external party who understands the timing of the upload event. The ability to locate and download these files facilitates further attacks, such as information disclosure, social engineering using stolen content, or leveraging exposed internal resources for lateral movement within an organization's network infrastructure.
This vulnerability aligns closely with CWE-330: Use of Insufficiently Random Values, which categorizes flaws where random values are used in security-critical contexts but lack the necessary entropy to prevent prediction. Additionally, it relates to CWE-598: Use of GET Request Method With Sensitive Query Strings if the filenames are exposed via URL parameters during access attempts, although the primary issue is the predictability itself. In terms of offensive security frameworks like MITRE ATT&CK, this behavior supports techniques associated with Collection and Exfiltration over C2 channels or direct network transfer, as it enables unauthorized data retrieval that bypasses standard authentication controls designed to protect uploaded assets. The predictability essentially renders any access control lists tied to the file identity ineffective because the identifier itself is not secret.
To mitigate this risk, organizations must ensure they are running version 14.0101 or later of the application, as indicated by the vendor patch available at https://vsdesk.ru/. This update addresses the underlying generation logic for uploaded filenames, replacing the timestamp-based method with a secure alternative that incorporates sufficient entropy to prevent prediction. For environments where immediate upgrading is not feasible due to compatibility constraints, temporary mitigations should include implementing strict access controls on the upload directory itself, such as denying direct web server execution or listing of files in those directories via HTTP GET requests unless explicitly authorized by application logic rather than file existence alone. Furthermore, integrating a Content Delivery Network with WAF rules that detect and block sequential filename probing patterns can provide an additional layer of defense against brute-force enumeration attempts until the software is fully patched.