CVE-2008-4041 in Softalk Mail Server
Summary
by MITRE
The IMAP server in Softalk Mail Server (formerly WorkgroupMail) 8.5.1.431 allows remote authenticated users to cause a denial of service (resource consumption and daemon crash) via a long IMAP APPEND command with certain repeated parameters.
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Analysis
by VulDB Data Team • 01/19/2025
The vulnerability identified as CVE-2008-4041 affects the IMAP server component of Softalk Mail Server version 8.5.1.431, formerly known as WorkgroupMail. This represents a significant security flaw that enables authenticated remote attackers to execute a denial of service attack against the mail server daemon. The vulnerability specifically targets the IMAP protocol implementation within the server software, exploiting a weakness in how the system processes certain command parameters. The affected software operates as a mail server solution that provides IMAP services for email retrieval and management, making it a critical component in enterprise email infrastructure.
The technical flaw manifests through the improper handling of the IMAP APPEND command when executed with specific repeated parameters. When an authenticated user sends a crafted APPEND command containing excessively long parameter sequences with repeated elements, the server fails to properly validate or limit the resource consumption during command processing. This leads to excessive memory allocation and CPU utilization, ultimately causing the IMAP daemon to consume all available system resources and crash. The vulnerability stems from inadequate input validation and resource management within the IMAP server implementation, creating a condition where legitimate authenticated users can abuse the system's resource handling mechanisms.
The operational impact of this vulnerability extends beyond simple service disruption, as it can severely compromise email availability for legitimate users within the organization. The denial of service attack can render the entire IMAP service inaccessible, preventing users from accessing their email accounts, retrieving messages, or performing standard email operations. This vulnerability is particularly dangerous because it requires only authenticated access, meaning that any user with valid credentials can potentially trigger the service disruption. The daemon crash affects not just the IMAP service but may also impact other related services running on the same server instance, leading to broader system instability. Organizations relying on this mail server for business communications face significant operational risks, including potential data access delays and communication disruptions that could affect productivity and business continuity.
Mitigation strategies for this vulnerability should focus on both immediate defensive measures and long-term architectural improvements. The most effective immediate solution involves applying the vendor-provided security patch or upgrade to a version that addresses the resource handling issue in the IMAP server implementation. Organizations should also implement network-level monitoring to detect unusual patterns of APPEND command usage that might indicate exploitation attempts. Access controls and user privilege management should be reviewed to minimize the potential impact of authenticated users who could exploit this vulnerability. Additionally, implementing resource limits and command timeouts on the IMAP server can help prevent excessive consumption of system resources. This vulnerability aligns with CWE-770, which addresses allocation of resources without limits or with inadequate limits, and represents a specific instance of the broader ATT&CK technique T1499.004 for Network Denial of Service. Organizations should also consider implementing intrusion detection systems to monitor for patterns consistent with this specific attack vector and establish incident response procedures to quickly address any exploitation attempts.