CVE-2003-1266 in EServ
Summary
by MITRE
The (1) FTP, (2) POP3, (3) SMTP, and (4) NNTP servers in EServer 2.92 through 2.97, and possibly 2.98, allow remote attackers to cause a denial of service (crash) via a large amount of data.
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Analysis
by VulDB Data Team • 01/26/2025
The vulnerability described in CVE-2003-1266 represents a critical denial of service weakness affecting multiple network service protocols within EServer versions 2.92 through 2.97, with potential impact extending to version 2.98. This issue manifests across four fundamental mail and file transfer protocols including File Transfer Protocol, Post Office Protocol version 3, Simple Mail Transfer Protocol, and Network News Transfer Protocol. The flaw demonstrates a classic buffer overflow or input validation failure where the affected servers fail to properly handle excessive data inputs, leading to system instability and potential complete service disruption.
The technical implementation of this vulnerability stems from inadequate input sanitization and memory management within the server's protocol handling components. When remote attackers submit large volumes of data to any of these four protocols, the servers process the input without proper bounds checking or data length validation. This condition creates a situation where the server's memory buffers overflow or become corrupted, resulting in immediate system crashes and service termination. The vulnerability operates at the application layer and affects the core protocol handlers that manage client connections and data processing for each respective service.
From an operational perspective, this vulnerability presents a significant risk to organizations relying on EServer for their email and file transfer infrastructure. The impact extends beyond simple service interruption as attackers can exploit this weakness to repeatedly crash multiple critical services simultaneously, effectively rendering the entire server platform unusable. The remote nature of the attack means that any attacker with network access can trigger the vulnerability without requiring local system privileges or specialized equipment. This makes the exploit particularly dangerous in environments where network exposure is high, as the attack can be executed from anywhere on the internet.
The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and demonstrates characteristics consistent with CWE-122, heap-based buffer overflow scenarios, as well as CWE-770, which covers allocation of resources without limits or throttling. From an adversary perspective, this vulnerability maps to ATT&CK technique T1499.004, specifically focusing on network denial of service attacks, and represents a low-effort, high-impact method for disrupting services. The exploitability factor is particularly concerning as it requires minimal technical skill to execute, making it attractive to threat actors seeking to disrupt operations without extensive preparation.
Organizations should implement immediate mitigations including input rate limiting, connection throttling, and implementing proper data length validation for all protocol handlers. Network segmentation and firewall rules should restrict access to these services where possible, while regular monitoring should detect unusual connection patterns that might indicate exploitation attempts. The most effective long-term solution involves upgrading to patched versions of EServer or migrating to more modern, secure server implementations that properly handle large data inputs through robust input validation and memory management practices.