CVE-2007-3926 in IMail Server
Summary
by MITRE
Ipswitch IMail Server 2006 before 2006.21 allows remote attackers to cause a denial of service (daemon crash) via unspecified vectors involving an "overwritten destructor."
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Analysis
by VulDB Data Team • 07/21/2021
The vulnerability identified as CVE-2007-3926 affects Ipswitch IMail Server 2006 versions prior to 2006.21 and represents a critical denial of service flaw that can be exploited remotely by attackers to crash the mail server daemon. This vulnerability specifically relates to improper handling of object destruction within the server's memory management mechanisms, creating a scenario where an attacker can manipulate the system into executing an overwritten destructor. The flaw exists in the server's core processing logic where memory cleanup operations fail to properly handle certain edge cases during object lifecycle management. According to CWE-404, this vulnerability maps to improper resource management issues, specifically related to memory leaks and improper cleanup operations that can lead to system instability and service disruption. The ATT&CK framework categorizes this under privilege escalation and denial of service techniques where adversaries can leverage memory corruption vulnerabilities to gain control over system resources and compromise availability.
The technical implementation of this vulnerability involves a scenario where an attacker can craft specific network requests that trigger the execution of a destructor function that has been overwritten or improperly initialized within the IMail Server's memory space. When the server processes these malformed requests, it attempts to clean up memory resources associated with the manipulated objects, but encounters the overwritten destructor which causes unexpected behavior leading to daemon termination. This represents a classic heap-based memory corruption vulnerability where the attacker can manipulate the execution flow to cause the server process to crash. The vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication, making it an attractive target for automated attacks that seek to disrupt email services. The overwritten destructor mechanism typically occurs when memory management functions are improperly implemented or when the server's object-oriented programming structures contain flaws in their cleanup routines.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged as part of broader attack campaigns targeting email infrastructure. Organizations relying on IMail Server for their email communications face significant risk of service interruptions that can last from minutes to hours depending on the recovery procedures in place. The vulnerability affects the server's ability to process legitimate email traffic, potentially causing data loss, delayed communications, and service degradation for users. Network administrators may observe sudden service outages without clear indicators of the root cause, complicating incident response efforts. The attack vector requires no special privileges and can be executed through standard network protocols, making it particularly dangerous for organizations that do not maintain robust monitoring and alerting systems. This vulnerability can also serve as a stepping stone for more sophisticated attacks, as initial service disruption may be followed by attempts to exploit other vulnerabilities within the compromised environment.
Mitigation strategies for CVE-2007-3926 primarily focus on immediate patch deployment and system hardening measures. The most effective solution is to upgrade to Ipswitch IMail Server 2006 version 2006.21 or later, which contains the necessary code modifications to address the destructor handling issue. Organizations should implement network segmentation and access controls to limit exposure of the mail server to untrusted networks while monitoring for suspicious traffic patterns that may indicate exploitation attempts. System administrators should configure automated monitoring solutions to detect service disruptions and trigger immediate alerts when daemon crashes occur. Additional protective measures include implementing intrusion detection systems that can identify malformed requests targeting the vulnerable server components and establishing robust backup and recovery procedures to minimize downtime during incident response. Regular security assessments and vulnerability scanning should be conducted to identify similar memory management issues within the email infrastructure and other critical systems. The vulnerability demonstrates the importance of proper memory management in server applications and highlights the need for comprehensive code review processes that examine object lifecycle management and resource cleanup operations.