CVE-2001-0691 in Imapd
Summary
by MITRE
Buffer overflows in Washington University imapd 2000a through 2000c could allow local users without shell access to execute code as themselves in certain configurations.
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Analysis
by VulDB Data Team • 10/05/2025
The vulnerability identified as CVE-2001-0691 represents a critical buffer overflow flaw within the Washington University imapd 2000a through 2000c email server implementations. This vulnerability specifically affects the Internet Message Access Protocol daemon that handles email retrieval and management operations. The buffer overflow occurs during the processing of certain input parameters, creating an opportunity for exploitation that could lead to unauthorized code execution within the target system's security boundaries.
The technical flaw manifests when the imapd daemon processes user-supplied input without proper bounds checking, allowing maliciously crafted input to overwrite adjacent memory locations in the program's stack. This particular vulnerability is classified as a stack-based buffer overflow, which falls under the CWE-121 category of stack-based buffer overflow conditions. The flaw exists in the authentication and command processing mechanisms of the imapd service, where insufficient input validation permits attackers to inject malicious data that exceeds the allocated buffer space.
The operational impact of this vulnerability is significant for systems running the affected imapd versions, as it enables local users who lack direct shell access to potentially escalate their privileges and execute arbitrary code within the context of their own user account. This represents a privilege escalation vector that could be leveraged by malicious actors to gain unauthorized access to email accounts and potentially compromise the broader system. The vulnerability's impact is particularly concerning because it allows execution in the context of the target user without requiring root privileges, making it more accessible to attackers who may have limited initial access.
The exploitation of this vulnerability requires careful crafting of input data that specifically targets the buffer overflow condition in the imapd daemon. Attackers typically need to understand the memory layout of the target process and the specific input processing functions that are vulnerable. This vulnerability aligns with the ATT&CK technique T1068 which involves exploiting vulnerabilities in legitimate applications to gain access to systems. The attack surface is particularly relevant in environments where multiple users access shared email systems, as the vulnerability could be exploited to gain unauthorized access to other users' email accounts and data.
Mitigation strategies for CVE-2001-0691 should prioritize immediate patching of the affected imapd versions to the latest stable releases from Washington University. Organizations should implement network segmentation to limit access to email servers and reduce the attack surface available to potential attackers. Additionally, system administrators should conduct regular security audits to identify and remediate similar buffer overflow vulnerabilities in other network services. The implementation of input validation controls and runtime protection mechanisms such as stack canaries can help prevent exploitation of similar buffer overflow conditions. Security monitoring should be enhanced to detect suspicious authentication patterns and unusual command processing activities that may indicate exploitation attempts. Organizations should also consider implementing privilege separation mechanisms to limit the potential damage from successful exploitation attempts, ensuring that even if a buffer overflow is successfully exploited, the attacker's capabilities remain restricted to the privileges of the compromised user account.