CVE-2025-5253: Kron PAM HTTP DoS Vulnerability

CVE-2025-5253 Overview

CVE-2025-5253 is a resource exhaustion vulnerability in Kron Technologies Kron Privileged Access Management (PAM) that enables HTTP-based denial of service. The flaw is classified under [CWE-770] Allocation of Resources Without Limits or Throttling. An authenticated attacker with low privileges can send crafted HTTP traffic that consumes server resources without bound, degrading or halting availability of the PAM service. The issue affects Kron PAM releases prior to version 3.7.

Critical Impact
Successful exploitation renders Kron PAM unavailable, disrupting privileged session brokering and credential vaulting workflows that downstream administrative operations depend on.

Affected Products

Kron Technologies Kron PAM versions before 3.7
Deployments exposing the Kron PAM HTTP interface to authenticated users
Environments relying on Kron PAM for privileged session management

Discovery Timeline

2025-07-25 - CVE-2025-5253 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-5253

Vulnerability Analysis

The vulnerability resides in Kron PAM's handling of HTTP requests. The application accepts and processes requests without enforcing sufficient limits on resource allocation. An authenticated attacker can issue requests that force the server to allocate memory, threads, or connection handles beyond safe operational bounds.

Because Kron PAM brokers privileged access, an availability failure blocks administrators from reaching downstream infrastructure through the vault. The impact is limited to availability; confidentiality and integrity are not affected according to the published vector.

Root Cause

The root cause is missing throttling and quota enforcement on server-side resources triggered by HTTP request handling ([CWE-770]). The application does not cap per-user request rates, request body sizes, concurrent sessions, or backend resource consumption tied to request processing. Under abusive request patterns, this leads to exhaustion of finite resources such as heap memory, worker threads, or database connections.

Attack Vector

Exploitation requires network access to the Kron PAM HTTP endpoint and a valid low-privileged account. No user interaction is needed. The attacker submits repeated or resource-intensive HTTP requests that the server processes without back-pressure. Sustained traffic exhausts allocated resources, causing the service to become unresponsive to legitimate administrators. Public proof-of-concept code is not available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Refer to the USOM Notification TR-25-0178 and the Siber Güvenlik Notification TR-25-0178 for vendor-coordinated advisory details.

Detection Methods for CVE-2025-5253

Indicators of Compromise

Sudden spikes in HTTP request volume from a single authenticated Kron PAM account
Elevated memory, CPU, or thread utilization on Kron PAM application servers with no corresponding administrative workload
Increased HTTP 5xx responses or connection timeouts from the Kron PAM front end
Repeated large or long-running HTTP requests originating from internal client subnets

Detection Strategies

Baseline normal request rates per authenticated user and alert on statistically significant deviations
Inspect web server and reverse proxy logs for repeated identical or oversized POST bodies to Kron PAM endpoints
Correlate authentication events with request-rate anomalies to identify abusive low-privileged accounts

Monitoring Recommendations

Enable verbose HTTP access logging on Kron PAM and forward logs to a centralized analytics platform
Monitor JVM or application runtime metrics for sustained resource growth without release
Track availability of Kron PAM through synthetic health checks and alert on service degradation

How to Mitigate CVE-2025-5253

Immediate Actions Required

Upgrade Kron PAM to version 3.7 or later, which addresses the unbounded resource allocation flaw
Restrict network reachability of the Kron PAM HTTP interface to trusted administrative networks
Audit and disable unused low-privileged Kron PAM accounts that could be leveraged for authenticated abuse
Rotate credentials for any accounts suspected of being exposed prior to patching

Patch Information

Kron Technologies has resolved the issue in Kron PAM 3.7. All prior releases are affected and should be upgraded. Consult the USOM Notification TR-25-0178 for the vendor-coordinated advisory and upgrade guidance.

Workarounds

Place a web application firewall or reverse proxy in front of Kron PAM to enforce per-source request rate limits
Cap request body sizes and concurrent connections at the proxy layer to prevent resource amplification
Configure connection and request timeouts to reclaim resources tied up by slow or oversized requests
Segment Kron PAM administrative access behind VPN or jump hosts to reduce the population of accounts able to reach the vulnerable endpoint

bash

# Configuration example: NGINX request throttling in front of Kron PAM
http {
    limit_req_zone $binary_remote_addr zone=kronpam:10m rate=10r/s;
    limit_conn_zone $binary_remote_addr zone=kronpam_conn:10m;

    server {
        listen 443 ssl;
        server_name kronpam.example.local;

        client_max_body_size 1m;
        client_body_timeout 10s;
        send_timeout 10s;

        location / {
            limit_req zone=kronpam burst=20 nodelay;
            limit_conn kronpam_conn 10;
            proxy_pass https://kronpam_backend;
        }
    }
}