CVE-2025-25055: FileMegane Auth Bypass Vulnerability

CVE-2025-25055 Overview

CVE-2025-25055 is an authentication bypass by spoofing vulnerability affecting FileMegane versions above 1.0.0.0 and prior to 3.4.0.0. The flaw allows a remote attacker to impersonate a legitimate user and access restricted file contents without valid credentials. The weakness maps to [CWE-290: Authentication Bypass by Spoofing].

The vulnerability is exploitable over the network without user interaction or prior authentication. Successful exploitation exposes confidential file contents managed by the FileMegane application.

Critical Impact
Remote attackers can spoof authentication to impersonate users and read restricted files stored in FileMegane.

Affected Products

FileMegane versions above 1.0.0.0
FileMegane versions prior to 3.4.0.0
Deployments exposing FileMegane authentication interfaces over the network

Discovery Timeline

2025-02-18 - CVE-2025-25055 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-25055

Vulnerability Analysis

The vulnerability resides in the authentication layer of FileMegane, a file management product. An attacker can craft requests that spoof the identity of another user, bypassing verification controls. Once impersonation succeeds, the attacker gains the impersonated user's access to file contents.

The impact is limited to confidentiality of stored files. Integrity and availability of the system remain unaffected by the flaw itself. Detailed technical information is available in the JVN Advisory JVN80527854 and the Info-BRDG Security Report.

Root Cause

The root cause is insufficient validation of identity claims during authentication [CWE-290]. FileMegane accepts identity attributes that can be spoofed by an unauthenticated remote attacker. Because trust decisions rely on data an attacker can influence, the server misattributes requests to legitimate accounts.

Attack Vector

Exploitation occurs over the network against exposed FileMegane instances. The attacker requires no privileges and no user interaction. By sending crafted authentication requests that assert another user's identity, the attacker gains that user's read access to restricted files. No public proof-of-concept exploit or CISA KEV listing is currently associated with this CVE.

Refer to the vendor advisory linked above for exploitation specifics rather than synthetic code, as no verified public exploit code is available.

Detection Methods for CVE-2025-25055

Indicators of Compromise

Unexpected successful authentication events for FileMegane user accounts originating from unfamiliar IP addresses
File access events attributed to users during periods when those users were not active
Access to restricted file paths from client sessions that never completed a full credentialed login

Detection Strategies

Correlate FileMegane authentication logs with source IP geolocation and historical user behavior to identify anomalous impersonation patterns
Alert on repeated authentication attempts that assert varying user identities from a single source
Monitor for file read events on restricted content without a preceding valid credential exchange

Monitoring Recommendations

Forward FileMegane application and web server logs to a centralized SIEM for retention and correlation
Establish baselines of normal user access hours and file access patterns to flag deviations
Track outbound data volumes from FileMegane servers for signs of bulk file exfiltration

How to Mitigate CVE-2025-25055

Immediate Actions Required

Upgrade FileMegane to version 3.4.0.0 or later to eliminate the authentication bypass
Restrict network access to FileMegane instances to trusted networks and VPN users only
Audit recent authentication and file access logs for evidence of impersonation activity

Patch Information

The vendor addresses the issue in FileMegane version 3.4.0.0. Administrators should follow the upgrade guidance provided in the Info-BRDG Security Report and the JVN Advisory JVN80527854.

Workarounds

Place FileMegane behind a reverse proxy that enforces additional authentication such as mutual TLS
Limit access to the FileMegane service using firewall rules that whitelist known client subnets
Rotate credentials for any accounts suspected of being impersonated prior to patching

bash

# Example: restrict FileMegane access via host firewall to a trusted subnet
# Replace 10.10.0.0/24 with your trusted management network
iptables -A INPUT -p tcp --dport 443 -s 10.10.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP