CVE-2004-2583 in SmarterMail
Summary
by MITRE
SMTP service in SmarterTools SmarterMail 1.6.1511 and 1.6.1529 allows remote attackers to cause a denial of service (CPU consumption) via a large number of simultaneous open connections to TCP port 25.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 06/30/2018
The vulnerability described in CVE-2004-2583 represents a classic denial of service flaw affecting the SMTP service implementation within SmarterTools SmarterMail versions 1.6.1511 and 1.6.1529. This issue stems from inadequate connection handling mechanisms that fail to properly manage concurrent connections to the standard SMTP port 25. The flaw operates by exploiting the service's inability to effectively throttle or limit simultaneous connection attempts, creating a scenario where malicious actors can overwhelm the system through excessive parallel connection requests.
The technical exploitation of this vulnerability leverages the fundamental TCP connection model used by SMTP services, where each connection attempt consumes system resources including CPU cycles and memory allocation. When attackers establish a large number of simultaneous connections to port 25, the SmarterMail service becomes overwhelmed with connection management overhead, leading to excessive CPU utilization and ultimately rendering the service unavailable to legitimate users. This behavior aligns with CWE-400, which categorizes unchecked resource consumption as a significant security weakness in system design. The vulnerability demonstrates poor resource management practices that violate fundamental security principles of robust system design and resource isolation.
From an operational impact perspective, this vulnerability creates substantial disruption to email services by effectively shutting down the SMTP functionality of the affected system. Organizations relying on SmarterMail for email communication would experience complete email service outages, impacting business operations and user productivity. The attack vector requires minimal sophistication and can be executed by any attacker with network access to the target system, making it particularly dangerous in environments where email services are critical for business operations. The resource exhaustion occurs at the application level rather than at the network infrastructure level, meaning traditional network-based DoS protections may not be effective against this specific attack pattern.
The mitigation strategies for this vulnerability should focus on implementing connection rate limiting and resource throttling mechanisms at multiple levels. Network-level firewalls should be configured to limit the number of concurrent connections to port 25 from any single source address, while the application itself should implement connection pooling and timeout mechanisms to prevent indefinite resource consumption. System administrators should also consider implementing intrusion detection systems that can identify unusual connection patterns and automatically trigger protective measures. According to ATT&CK framework category T1498, which covers resource exhaustion attacks, this vulnerability represents a specific implementation weakness that can be addressed through proper system hardening and resource management configurations. The most effective long-term solution involves upgrading to a patched version of SmarterMail that properly implements connection management and resource allocation controls to prevent the exploitation of this vulnerability.