CVE-2019-25613: Easy Chat Server 3.1 DoS Vulnerability

CVE-2019-25613 Overview

Easy Chat Server 3.1 contains a denial of service vulnerability that allows remote attackers to crash the application by sending oversized data in the message parameter. Attackers can establish a session via the chat.ghp endpoint and then send a POST request to body2.ghp with an excessively large message parameter value to cause the service to crash.

Critical Impact

Remote attackers can cause complete service disruption without authentication, affecting all users relying on the Easy Chat Server for communication services.

Affected Products

• Easy Chat Server 3.1

Discovery Timeline

• 2026-03-22 - CVE CVE-2019-25613 published to NVD
• 2026-03-23 - Last updated in NVD database

Technical Details for CVE-2019-25613

Vulnerability Analysis

This vulnerability is classified under CWE-940 (Improper Verification of Source of a Communication Channel). The flaw exists in the message handling functionality of Easy Chat Server 3.1, specifically in how the application processes incoming message data through the body2.ghp endpoint.

The application fails to properly validate the size of data submitted through the message parameter before processing it. When an attacker sends an oversized payload, the server attempts to handle the malformed input, leading to resource exhaustion or memory corruption that results in a complete application crash.

The attack can be executed remotely over the network without requiring any prior authentication or special privileges. The vulnerability affects the availability of the service while confidentiality and integrity remain unaffected.

Root Cause

The root cause stems from improper input validation in the message handling component. Easy Chat Server 3.1 does not enforce adequate boundary checks on the message parameter received via POST requests to body2.ghp. This allows attackers to submit arbitrarily large data that exceeds the application's processing capacity, resulting in a denial of service condition.

Attack Vector

The attack follows a two-step process. First, an attacker establishes a valid session by connecting to the chat.ghp endpoint on the target Easy Chat Server. Once a session is established, the attacker crafts a POST request to body2.ghp containing an excessively large value in the message parameter. When the server attempts to process this oversized message, it exhausts available resources and crashes, denying service to all legitimate users.

This network-based attack requires no authentication and no user interaction, making it trivially exploitable by any attacker with network access to the vulnerable server. Technical details and exploitation methods are documented in the Exploit-DB #46806 entry.

Detection Methods for CVE-2019-25613

Indicators of Compromise

• Unusually large HTTP POST requests to the body2.ghp endpoint
• Sudden service crashes or restarts of the Easy Chat Server process
• Network traffic containing oversized message parameter values
• Error logs indicating memory allocation failures or buffer issues

Detection Strategies

• Monitor HTTP traffic for POST requests to body2.ghp with abnormally large payloads
• Implement network intrusion detection rules to alert on requests exceeding expected message sizes
• Configure application performance monitoring to detect sudden service terminations
• Review web server access logs for suspicious patterns targeting chat endpoints

Monitoring Recommendations

• Deploy web application firewall (WAF) rules to limit POST body sizes to expected thresholds
• Enable verbose logging on the Easy Chat Server to capture request details before crashes
• Set up automated alerts for service availability monitoring with rapid notification on downtime
• Monitor system resource utilization for anomalous memory or CPU spikes preceding crashes

How to Mitigate CVE-2019-25613

Immediate Actions Required

• Restrict network access to the Easy Chat Server to trusted IP ranges or internal networks only
• Deploy a reverse proxy or WAF in front of the server to filter oversized requests
• Consider disabling the service until a patch can be applied if it is publicly exposed
• Implement request size limits at the network perimeter

Patch Information

No vendor patch information is currently available for this vulnerability. Users should contact the vendor directly via the EchatServer Homepage for remediation guidance. The VulnCheck Advisory on Echat Server provides additional context on the vulnerability status.

Workarounds

• Place the Easy Chat Server behind a reverse proxy that enforces maximum POST body size limits
• Configure firewall rules to restrict access to the body2.ghp endpoint from untrusted networks
• Implement rate limiting on incoming connections to reduce the impact of repeated attack attempts
• Consider migrating to an alternative chat server solution that receives active security maintenance

# Configuration example - Nginx reverse proxy with request size limit
# Add to server block protecting Easy Chat Server

location /body2.ghp {
    client_max_body_size 1m;
    proxy_pass http://localhost:8080;
    limit_req zone=chat_limit burst=5 nodelay;
}

# Define rate limiting zone in http block
# limit_req_zone $binary_remote_addr zone=chat_limit:10m rate=10r/s;