CVE-2018-25193 Overview
CVE-2018-25193 is a denial of service vulnerability affecting Mongoose Web Server version 6.9. This vulnerability allows remote attackers to crash the service by establishing multiple socket connections. Attackers can repeatedly create connections to the default port and send malformed data to exhaust server resources and cause service unavailability.
Critical Impact
Remote attackers can cause complete service disruption by exhausting server resources through repeated malformed socket connections, resulting in denial of service for legitimate users.
Affected Products
- Mongoose Web Server 6.9
Discovery Timeline
- 2026-03-06 - CVE-2018-25193 published to NVD
- 2026-03-09 - Last updated in NVD database
Technical Details for CVE-2018-25193
Vulnerability Analysis
This denial of service vulnerability stems from improper resource management in Mongoose Web Server 6.9. The server fails to adequately limit or manage incoming socket connections, allowing an attacker to overwhelm the service by opening numerous connections simultaneously. When combined with malformed data sent through these connections, the server's resources become exhausted, leading to service unavailability.
The vulnerability is classified under CWE-1188 (Insecure Default Initialization of Resource), indicating that the default configuration does not implement sufficient safeguards against resource exhaustion attacks. This makes freshly installed or default-configured instances particularly susceptible to exploitation.
Root Cause
The root cause of this vulnerability lies in the insecure default configuration of Mongoose Web Server 6.9. The server does not implement adequate connection rate limiting or resource management controls out of the box. This allows attackers to establish an excessive number of socket connections without proper throttling or validation, ultimately exhausting available server resources such as memory, file descriptors, or processing capacity.
Attack Vector
The attack is network-based and can be executed remotely without authentication. An attacker initiates the attack by establishing multiple concurrent socket connections to the Mongoose Web Server's default port. The attack sequence typically involves:
- Opening numerous TCP connections to the target server
- Sending malformed or crafted data packets through these connections
- Maintaining connections to prevent resource release
- Repeating the process to completely exhaust server resources
The attack does not require any user interaction and can be launched from any network location with connectivity to the vulnerable server. Technical details and proof-of-concept information are available in the Exploit-DB #45819 advisory.
Detection Methods for CVE-2018-25193
Indicators of Compromise
- Unusual spike in the number of concurrent TCP connections to the Mongoose Web Server port
- Server process consuming abnormally high memory or CPU resources
- Rapid increase in connection establishment attempts from single or multiple source IPs
- Service becoming unresponsive or crashing unexpectedly
Detection Strategies
- Implement network monitoring to detect anomalous connection patterns targeting the web server port
- Configure intrusion detection systems (IDS) to alert on high-volume connection attempts
- Monitor server logs for repeated connection failures or resource exhaustion errors
- Deploy rate-limiting rules at the network perimeter to identify potential DoS attempts
Monitoring Recommendations
- Set up alerts for connection count thresholds exceeding normal operational baselines
- Monitor system resource utilization (memory, CPU, file descriptors) for the Mongoose process
- Implement log aggregation to correlate connection events across multiple time periods
- Review network flow data for patterns consistent with connection flooding attacks
How to Mitigate CVE-2018-25193
Immediate Actions Required
- Implement connection rate limiting at the network or application layer
- Configure firewall rules to restrict access to the Mongoose Web Server to trusted IP ranges
- Consider deploying the server behind a reverse proxy with DoS protection capabilities
- Upgrade to a patched version of Mongoose Web Server if available
Patch Information
Consult the VulnCheck Advisory on Mongoose DoS for the latest information on available patches and recommended versions. Organizations should verify vendor documentation for the most current remediation guidance.
Workarounds
- Deploy a web application firewall (WAF) or reverse proxy in front of the Mongoose Web Server to filter malicious traffic
- Implement operating system-level connection limits using tools like iptables or nftables
- Configure resource limits (ulimits) for the Mongoose process to prevent complete system exhaustion
- Enable connection timeout settings to automatically close idle or suspicious connections
# Example iptables rate limiting configuration
# Limit new connections to 25 per minute per source IP
iptables -A INPUT -p tcp --dport 8080 -m state --state NEW -m recent --set
iptables -A INPUT -p tcp --dport 8080 -m state --state NEW -m recent --update --seconds 60 --hitcount 25 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
