CVE-2025-46390: Observable Response Discrepancy Vulnerability

CVE-2025-46390 Overview

CVE-2025-46390 is an Observable Response Discrepancy vulnerability (CWE-204) that allows attackers to extract sensitive information through differences in application responses. This type of vulnerability occurs when an application reveals different behaviors or responses based on internal state, allowing attackers to infer confidential information through systematic probing of the system.

Critical Impact

This vulnerability enables information disclosure through observable differences in application responses, potentially allowing attackers to enumerate valid users, discover sensitive data, or map internal system states through network-based attacks requiring no authentication or user interaction.

Affected Products

• Specific affected products have not been disclosed in the available CVE data
• See the Israeli Government CVE Advisories for additional product information

Discovery Timeline

• 2025-08-06 - CVE-2025-46390 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-46390

Vulnerability Analysis

This vulnerability falls under CWE-204: Observable Response Discrepancy, which occurs when an application produces different observable responses based on internal conditions that should remain hidden from external observers. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, making it accessible to unauthenticated attackers.

Observable response discrepancies can manifest in various ways including timing differences, error message variations, HTTP status code changes, or different response content lengths. Attackers can leverage these discrepancies to enumerate valid usernames, determine the existence of resources, or extract other sensitive information bit by bit through oracle attacks.

Root Cause

The root cause of CWE-204 vulnerabilities lies in application logic that fails to provide consistent responses regardless of internal state. When an application reveals whether a condition is true or false through observable differences—such as returning "invalid username" versus "invalid password" during authentication—it creates an information oracle that attackers can systematically query.

Attack Vector

The attack vector is network-based, allowing remote attackers to exploit this vulnerability without any privileges or user interaction. An attacker can craft requests designed to elicit different responses based on internal application state. By analyzing the variations in responses (timing, content, status codes, or error messages), the attacker can infer sensitive information.

Typical exploitation involves:

1. Identifying an endpoint that produces varying responses based on internal conditions
2. Crafting requests that probe specific conditions (e.g., username existence)
3. Analyzing response differences to extract information
4. Iterating through possible values to enumerate sensitive data

For detailed technical information regarding this vulnerability, please refer to the Israeli Government CVE Advisories.

Detection Methods for CVE-2025-46390

Indicators of Compromise

• Unusual patterns of sequential or systematic requests to authentication or lookup endpoints
• High volume of similar requests with slight parameter variations from a single source
• Requests that appear to be probing for valid usernames, account numbers, or other enumerable values
• Automated tools or scripts attempting to measure response timing or content differences

Detection Strategies

• Monitor for enumeration attack patterns in authentication and lookup endpoints
• Implement rate limiting and anomaly detection for endpoints susceptible to oracle attacks
• Deploy Web Application Firewalls (WAF) with rules to detect enumeration attempts
• Analyze logs for patterns of failed authentication attempts with varying usernames

Monitoring Recommendations

• Enable detailed logging on sensitive endpoints to capture request patterns
• Configure alerting for high-frequency requests to authentication or data lookup endpoints
• Monitor response timing metrics for anomalies that could indicate timing attack attempts
• Implement SIEM rules to correlate enumeration patterns across multiple endpoints

How to Mitigate CVE-2025-46390

Immediate Actions Required

• Review authentication and error handling logic to ensure consistent response behavior
• Implement generic error messages that do not reveal whether specific conditions are true or false
• Add artificial delays or consistent response times to prevent timing-based information disclosure
• Apply rate limiting to endpoints vulnerable to enumeration attacks

Patch Information

Specific patch information has not been disclosed in the available CVE data. Organizations should consult the Israeli Government CVE Advisories for vendor-specific patch guidance and updates.

Workarounds

• Implement uniform response messages for all authentication failures (e.g., "Invalid credentials" instead of distinguishing between invalid username and invalid password)
• Add consistent artificial delays to response handling to neutralize timing-based attacks
• Deploy CAPTCHA or progressive delays after multiple failed requests to mitigate automated enumeration
• Use account lockout mechanisms with consistent messaging regardless of account existence

# Example: Rate limiting configuration for NGINX
limit_req_zone $binary_remote_addr zone=auth_limit:10m rate=5r/m;

location /api/auth {
    limit_req zone=auth_limit burst=3 nodelay;
    # Additional configuration to ensure consistent response times
}