CVE-2025-41714: Path Traversal Vulnerability Overview

CVE-2025-41714 Overview

CVE-2025-41714 is a path traversal vulnerability [CWE-22] in an upload endpoint that fails to properly validate the Upload-Key request header. An authenticated attacker can supply directory traversal sequences in the header to write upload artifacts outside the intended storage directory. In permissive configurations, this primitive escalates to arbitrary file write and remote code execution (RCE). The flaw was published through CERT@VDE under advisory VDE-2025-085, indicating it affects an industrial or operational technology product.

Critical Impact
An authenticated network attacker can write arbitrary files outside the upload directory by injecting traversal sequences into the Upload-Key header, potentially achieving remote code execution on the host.

Affected Products

Product details disclosed via CERT@VDE advisory VDE-2025-085
Specific vendor and version information: Not Available in NVD data
Refer to the CERT@VDE Advisory VDE-2025-085 for affected component identification

Discovery Timeline

2025-09-10 - CVE-2025-41714 published to the National Vulnerability Database
2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-41714

Vulnerability Analysis

The vulnerability resides in the server-side handler that processes file uploads. The handler reads the Upload-Key HTTP request header and uses its value to construct a filesystem path for upload-related artifacts. The implementation does not sanitize traversal metacharacters such as ../ or absolute path indicators before joining the header value with the storage base directory.

An authenticated client can therefore steer file writes to arbitrary locations the service account can reach. Depending on deployment, attackers can drop scripts into web-served directories, overwrite configuration files, or plant binaries in autoloaded plugin paths. The CVSS vector indicates network reachability and a high impact across confidentiality, integrity, and availability, consistent with arbitrary file write leading to code execution.

Root Cause

The root cause is improper limitation of a pathname to a restricted directory [CWE-22]. The upload routine trusts an attacker-controlled header field as part of a filesystem path without canonicalizing the result or verifying that the resolved path remains inside the intended upload root.

Attack Vector

Exploitation requires valid authentication credentials but no user interaction. The attacker issues an HTTP upload request to the vulnerable endpoint and sets the Upload-Key header to a value containing traversal sequences such as ../../etc/cron.d/payload or a path pointing into a web root. The server resolves the path relative to its storage base and writes the uploaded content to the attacker-chosen location. Where the chosen location is later interpreted by another service, such as a scheduler, web server, or plugin loader, the write becomes code execution. See the CERT@VDE Advisory VDE-2025-085 for vendor-specific exploitation context.

Detection Methods for CVE-2025-41714

Indicators of Compromise

HTTP requests to upload endpoints containing ../, ..\, URL-encoded %2e%2e%2f, or absolute paths in the Upload-Key header
New or unexpected files appearing outside the configured upload storage directory, especially in web roots, scheduled task directories, or service plugin folders
Upload-handler process writing to filesystem locations not previously associated with its workload
Web shell or script files with recent modification times in directories served by the application

Detection Strategies

Inspect reverse proxy and application logs for the Upload-Key header and alert on values containing traversal metacharacters or encoded variants
Correlate authenticated upload activity with subsequent process executions originating from non-standard file paths
Apply file integrity monitoring to system directories, web roots, and service configuration paths reachable by the upload service account

Monitoring Recommendations

Enable verbose request logging on the upload endpoint, including all custom headers, and forward logs to a centralized analytics platform
Monitor child process creation by the upload service for shells, interpreters, or scripting engines that are not part of normal operation
Track outbound network connections from the host running the vulnerable service to identify post-exploitation command-and-control traffic

How to Mitigate CVE-2025-41714

Immediate Actions Required

Apply the vendor patch referenced in CERT@VDE Advisory VDE-2025-085 as soon as a fixed version is available
Restrict network access to the upload endpoint to trusted management networks until patching is complete
Rotate credentials for any account that could authenticate to the upload service, since exploitation requires low-privilege authentication
Audit the filesystem for unexpected files written outside the upload directory and investigate any matches as potential compromise

Patch Information

Consult the CERT@VDE Advisory VDE-2025-085 for the authoritative list of fixed versions and vendor remediation guidance. Specific patched build numbers are not enumerated in the NVD record at the time of publication.

Workarounds

Place a reverse proxy or web application firewall in front of the upload endpoint and block requests whose Upload-Key header contains .., /, \, or URL-encoded equivalents
Run the upload service under a dedicated low-privilege account with write access limited to the intended storage directory using filesystem ACLs or mount-level restrictions
Disable the upload feature entirely if it is not required for the current deployment

bash

# Example reverse-proxy guard (nginx) rejecting traversal attempts in Upload-Key
if ($http_upload_key ~* "(\.\.|%2e%2e|/|\\)") {
    return 400;
}