CVE-2002-1005 in Mail Server
Summary
by MITRE
ArGoSoft Mail Server 1.8.1.7 and earlier allows a webmail user to cause a denial of service (CPU consumption) by forwarding the email to the user while autoresponse is enabled, which creates an infinite loop.
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Analysis
by VulDB Data Team • 09/10/2025
The vulnerability described in CVE-2002-1005 represents a classic denial of service flaw within the ArGoSoft Mail Server software version 1.8.1.7 and earlier. This issue stems from a design flaw in the email handling mechanism that occurs when specific conditions are met during email processing. The vulnerability manifests when a webmail user enables autoresponse functionality while simultaneously forwarding emails to themselves, creating a scenario where the system enters an infinite loop of message processing. This particular flaw falls under the category of resource exhaustion attacks where malicious actors can consume system CPU resources indefinitely, effectively rendering the mail server unavailable to legitimate users. The vulnerability is particularly concerning as it requires minimal privileges to exploit, making it accessible to any user with webmail access to the affected system.
The technical root cause of this vulnerability lies in the improper handling of email forwarding and autoresponse mechanisms within the ArGoSoft Mail Server implementation. When an email is forwarded to a user who has autoresponse enabled, the system fails to detect the recursive forwarding scenario that would naturally occur when the autoresponse message is sent back to the original sender, who then forwards it again, creating an endless cycle. This behavior creates a condition where the mail server continuously processes the same email sequence without proper loop detection or termination logic. The flaw operates at the application layer and demonstrates poor input validation and state management within the email processing pipeline. According to CWE standards, this vulnerability maps to CWE-835, which describes the weakness of infinite loops or infinite recursion in software systems, and specifically relates to improper handling of recursive data structures or processing flows.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the overall availability and reliability of email services within affected organizations. When exploited, the infinite loop consumes CPU resources at maximum capacity, which can lead to complete system unresponsiveness or degradation of service quality for all users. Network administrators may observe sustained high CPU utilization on the mail server, making it difficult to distinguish between legitimate high-volume email processing and malicious exploitation. The vulnerability affects both the mail server's ability to process legitimate emails and its capacity to maintain system stability, potentially causing cascading failures in dependent services. Organizations relying on ArGoSoft Mail Server for email communications face significant risk of operational disruption, particularly in environments where email availability is critical for business operations.
Mitigation strategies for CVE-2002-1005 focus primarily on software updates and configuration hardening. The most effective immediate solution involves upgrading to a patched version of ArGoSoft Mail Server that addresses the recursive forwarding loop issue through proper loop detection mechanisms. System administrators should also implement configuration controls that disable autoresponse features for users who do not require them, particularly in environments where email forwarding is commonly used. Network monitoring solutions should be configured to detect unusual CPU utilization patterns that may indicate exploitation attempts. The implementation of rate limiting and resource quotas for email processing can help prevent single users from consuming excessive system resources. Additionally, organizations should consider implementing email filtering rules that prevent recursive forwarding scenarios from occurring in the first place. From an ATT&CK framework perspective, this vulnerability aligns with techniques related to resource exhaustion and denial of service, specifically targeting the availability aspect of the CIA triad. Regular vulnerability assessments and security audits should be conducted to identify similar loop conditions in other email processing systems and ensure proper implementation of defensive measures.