CVE-2025-53968: Evmapa Authentication DoS Vulnerability

CVE-2025-53968 Overview

CVE-2025-53968 is an authentication weakness in Evmapa that fails to limit the number of authentication attempts a user can submit. The vulnerability is classified under CWE-307 (Improper Restriction of Excessive Authentication Attempts). Attackers can flood the authentication endpoint with repeated requests, exhausting service resources and producing a denial-of-service (DoS) condition. The same weakness enables brute-force credential guessing against valid accounts. CISA published the issue in ICS Advisory ICSA-26-022-08, indicating relevance to operational technology environments.

Critical Impact
Unauthenticated network attackers can disrupt availability of the Evmapa authentication service and conduct unrestricted brute-force attempts against user credentials.

Affected Products

Evmapa Evmapa (all versions identified in the CISA ICS advisory)
Component: evmapa:evmapa
Operational Technology deployments referenced in ICSA-26-022-08

Discovery Timeline

2026-01-22 - CVE-2025-53968 published to NVD
2026-02-02 - Last updated in NVD database

Technical Details for CVE-2025-53968

Vulnerability Analysis

The Evmapa application does not enforce rate limiting, lockout thresholds, or backoff mechanisms on its authentication interface. Each authentication request is processed independently without tracking failed attempts per user, source IP, or session. An attacker reachable over the network can submit unlimited credential guesses without triggering account lockout or throttling.

The defect produces two distinct outcomes. First, sustained authentication traffic exhausts CPU, memory, or backend database connections on the authentication service, denying access to legitimate users. Second, the absence of attempt limits removes the primary control that makes password-based authentication resistant to automated guessing, allowing credential brute-force and password spraying.

The attack requires no privileges, no user interaction, and only network access to the authentication endpoint. The impact is confined to availability per the CVSS vector, though successful brute-force outcomes would extend impact to confidentiality and integrity through account takeover.

Root Cause

The root cause is the absence of authentication attempt accounting. The application lacks a counter that tracks consecutive failures, lacks a temporal window that decays attempts, and lacks a lockout mechanism that suspends authentication after threshold breach. This is a textbook CWE-307 implementation gap.

Attack Vector

The attack vector is network-based against the authentication interface. An attacker scripts a loop that issues authentication requests at high frequency. For DoS, the attacker generates request volume sufficient to saturate authentication service resources. For credential attack, the attacker iterates through dictionaries or breach corpora against known usernames. Both attack modes proceed without rate-limit feedback from the server.

No verified exploit code is publicly available for this CVE. Technical detail is documented in the CISA ICS Advisory ICSA-26-022-08 and the corresponding GitHub CSAF File.

Detection Methods for CVE-2025-53968

Indicators of Compromise

High volume of authentication requests from a single source IP or small set of IPs within a short window
Sustained failed-login events against multiple usernames originating from the same client
Authentication service latency spikes, connection pool exhaustion, or 5xx errors during sustained inbound login traffic
Successful authentication immediately following hundreds or thousands of failures for the same account

Detection Strategies

Aggregate authentication logs by source IP and username; alert when failure counts exceed defined thresholds per minute
Correlate authentication endpoint request volume with service health metrics to identify resource saturation events
Apply network flow analysis to identify abnormal request rates targeting Evmapa authentication URLs
Match credential-attempt patterns against password spraying signatures (low attempts per account, many accounts)

Monitoring Recommendations

Forward Evmapa authentication and web server logs to a centralized SIEM with retention sufficient for trend analysis
Baseline normal authentication request rates per source and alert on statistical deviations
Monitor host-level CPU, memory, and connection metrics on systems running Evmapa for capacity exhaustion
Track first-time-seen source IPs interacting with the authentication endpoint, especially from unexpected geographies

How to Mitigate CVE-2025-53968

Immediate Actions Required

Restrict network exposure of the Evmapa authentication interface to trusted management networks and VPN segments
Deploy a reverse proxy or web application firewall in front of Evmapa to enforce request rate limits per source IP
Review authentication logs for evidence of prior brute-force or DoS activity against the affected systems
Rotate credentials for any accounts that show anomalous authentication history

Patch Information

No vendor patch is referenced in the available NVD data or the CISA advisory at the time of publication. Consult the CISA ICS Advisory ICSA-26-022-08 for vendor remediation guidance and version updates as they become available.

Workarounds

Place Evmapa behind a reverse proxy that enforces per-IP and per-account rate limiting on authentication paths
Enforce network-layer access control lists that restrict authentication endpoints to authorized clients only
Require multi-factor authentication where supported to reduce the value of brute-forced passwords
Implement fail2ban-style log monitoring that blocks source IPs after a configurable number of failed attempts

bash

# Example: nginx rate limiting in front of the Evmapa authentication endpoint
http {
    limit_req_zone $binary_remote_addr zone=auth_limit:10m rate=5r/m;

    server {
        location /login {
            limit_req zone=auth_limit burst=3 nodelay;
            limit_req_status 429;
            proxy_pass http://evmapa_backend;
        }
    }
}