A denial of service vulnerability in Cesanta Mongoose Web Server 6.9 allows remote attackers to crash the service and disrupt availability via resource exhaustion.

This vulnerability is a resource exhaustion flaw, categorized as CWE-1188, which allows an unauthenticated remote attacker to cause a denial of service by establishing excessive socket connections and sending malformed data to the default port of the web server.

The successful exploitation of this vulnerability results in service unavailability, preventing legitimate users from accessing applications hosted on the affected Mongoose Web Server instance. Given the CVSS score of 7.5, this high severity flaw poses a significant risk to operational continuity, potentially leading to business disruption if the server is a critical component of the infrastructure.

Immediate Action: Upgrade to a version of Mongoose Web Server later than 6.9 where this resource handling flaw has been addressed.

Proactive Monitoring: Monitor server logs and system resource usage for spikes in connection counts or anomalous socket activity indicative of a denial of service attempt.

Compensating Controls: Deploy a Web Application Firewall or rate-limiting configuration on network perimeter devices to restrict the number of concurrent connections from a single source IP address.

Public Exploit Available: Yes, a published proof-of-concept exists in ExploitDB (EDB-ID: 45819).

The risk posed by this vulnerability is significant due to the ease of exploitation and the potential for complete service disruption. Organizations running Mongoose Web Server 6.9 should prioritize upgrading to a patched release immediately to eliminate the risk of remote service termination. If an immediate upgrade is not feasible, implement strict connection rate limiting at the network edge to mitigate the impact of potential exploitation attempts.