CVE-2025-3092 Overview
CVE-2025-3092 is an information disclosure vulnerability that allows an unauthenticated remote attacker to enumerate valid user names from an unprotected endpoint. The flaw is classified under [CWE-204: Observable Response Discrepancy], where the affected endpoint returns differing responses for valid versus invalid user names. Attackers can use this discrepancy to build lists of legitimate accounts without any credentials or user interaction. The vulnerability is documented in CERT@VDE advisories VDE-2025-035 and VDE-2025-038, which coordinate disclosures for industrial and embedded systems vendors.
Critical Impact
Remote, unauthenticated attackers can harvest valid user names over the network, enabling targeted credential attacks such as password spraying, brute force, and phishing.
Affected Products
- Products covered under CERT@VDE Advisory VDE-2025-035
- Products covered under CERT@VDE Advisory VDE-2025-038
- Refer to vendor advisories for the specific affected component versions
Discovery Timeline
- 2025-06-24 - CVE-2025-3092 published to NVD
- 2026-04-15 - Last updated in NVD database
Technical Details for CVE-2025-3092
Vulnerability Analysis
The vulnerability stems from an authentication or account-related endpoint that responds differently depending on whether a submitted user name exists in the system. Attackers send requests containing candidate user names and observe the server's response. Differences in HTTP status codes, response bodies, error messages, or response timing reveal which accounts are valid. The endpoint is exposed without any authentication or rate limiting, allowing automated enumeration at scale.
User name enumeration weaknesses [CWE-204] do not by themselves compromise confidentiality of stored data. They do, however, eliminate the obscurity layer that protects accounts from credential-guessing attacks. With a verified user list, attackers focus password spraying, multi-factor authentication (MFA) fatigue, and social engineering campaigns on accounts known to exist.
Root Cause
The root cause is an observable response discrepancy in an endpoint that should produce uniform responses regardless of account validity. Common implementation mistakes include returning distinct error strings such as user not found versus invalid password, returning different HTTP status codes, or processing valid accounts measurably slower than invalid ones.
Attack Vector
The attack vector is network-based and requires no authentication or user interaction. An attacker scripts requests to the vulnerable endpoint using a wordlist of candidate user names, then parses responses to extract the set of valid accounts. The enumerated list directly feeds follow-on attacks against the same system or any other system sharing the identity store.
No verified proof-of-concept code is publicly associated with this CVE. Consult the CERT@VDE Advisory VDE-2025-035 and CERT@VDE Advisory VDE-2025-038 for vendor-specific technical details.
Detection Methods for CVE-2025-3092
Indicators of Compromise
- Bursts of authentication or account-lookup requests from a single source IP using sequential or dictionary-derived user names
- High volumes of HTTP 4xx responses on the unauthenticated endpoint identified in the vendor advisory
- Repeated requests with varying username parameters and identical client fingerprints (User-Agent, TLS JA3)
Detection Strategies
- Establish a baseline for normal request volume to the affected endpoint and alert on statistical deviations
- Inspect web server and application logs for response-time anomalies between requests that succeed and fail
- Correlate enumeration patterns with subsequent authentication attempts against the same user names to identify multi-stage attacks
Monitoring Recommendations
- Forward web access logs and identity provider logs to a centralized analytics platform for cross-source correlation
- Track failed login distributions per source IP and per user name to surface spraying that follows enumeration
- Deploy network sensors in front of operational technology (OT) and industrial control system (ICS) interfaces, which are frequently in scope for CERT@VDE advisories
How to Mitigate CVE-2025-3092
Immediate Actions Required
- Apply the vendor patches referenced in CERT@VDE Advisory VDE-2025-035 and CERT@VDE Advisory VDE-2025-038
- Restrict network access to the affected endpoint using firewall rules, VPN gating, or network segmentation
- Enforce account lockout, MFA, and strong password policies to reduce the value of an enumerated user list
Patch Information
Vendor patches and version guidance are published in the CERT@VDE advisories listed in the external references. Operators should identify their specific product and firmware version against the advisory matrices and apply the recommended updates. Where patches are not yet available, follow the workarounds published in the same advisories.
Workarounds
- Place affected systems behind an authenticated reverse proxy or VPN so the vulnerable endpoint is not reachable from untrusted networks
- Apply rate limiting and CAPTCHA challenges to authentication-adjacent endpoints to slow automated enumeration
- Configure the application or a Web Application Firewall (WAF) to return uniform responses and constant-time behavior for valid and invalid user names
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
