CVE-2002-2357 in MailEnable
Summary
by MITRE
MailEnable 1.5 015 through 1.5 018 allows remote attackers to cause a denial of service (crash) via a long USER string, possibly due to a buffer overflow.
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Analysis
by VulDB Data Team • 06/04/2025
The vulnerability identified as CVE-2002-2357 affects MailEnable versions 1.5 015 through 1.5 018, representing a critical security flaw that enables remote attackers to execute denial of service attacks. This issue manifests when an attacker sends a specially crafted USER command containing an excessively long string to the mail server, causing the service to crash and become unavailable to legitimate users. The vulnerability stems from inadequate input validation mechanisms within the mail server's authentication process, specifically during USER command processing. The buffer overflow condition occurs when the server attempts to store the excessively long user string in a fixed-length buffer without proper bounds checking, leading to memory corruption that ultimately results in application termination.
The technical implementation of this vulnerability aligns with common buffer overflow patterns documented in the CWE (Common Weakness Enumeration) catalog under CWE-121, which describes heap-based buffer overflow conditions. The flaw operates at the protocol level where the mail server's implementation fails to properly validate the length of incoming USER command parameters. This allows an attacker to exceed the allocated buffer space and overwrite adjacent memory locations, causing unpredictable behavior including program crashes, system instability, and potential service disruption. The vulnerability specifically targets the SMTP protocol implementation within MailEnable, where the USER command is used during the authentication process to specify the recipient address for mail relaying operations.
From an operational impact perspective, this vulnerability presents significant risks to email server availability and reliability within corporate and organizational environments. The denial of service condition can be easily exploited by remote attackers without requiring authentication, making it particularly dangerous as it can be leveraged by malicious actors to disrupt email communications. The crash condition affects the entire mail service, potentially impacting business operations, customer communications, and internal email infrastructure. Organizations relying on MailEnable for their email services face substantial risk of service interruption, which could result in productivity losses, missed communications, and potential revenue impacts. The vulnerability also creates opportunities for attackers to perform reconnaissance activities or prepare for more sophisticated attacks by establishing a foothold through service disruption.
The recommended mitigation strategies for CVE-2002-2357 include immediate application of vendor patches or updates to MailEnable versions that address the buffer overflow vulnerability. Organizations should implement network-level protections such as input validation firewalls and intrusion detection systems to monitor and filter suspicious USER command patterns. Additionally, the implementation of proper input length validation and buffer management practices within the application code can help prevent similar issues in the future. Security teams should also consider implementing redundant email services or failover mechanisms to maintain availability during potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and memory management practices as outlined in the ATT&CK framework's defensive techniques related to input validation and memory protection. Organizations should also conduct regular vulnerability assessments and security audits to identify and remediate similar weaknesses in their email infrastructure and other network services.