CVE-2001-0825 in xinetd
Summary
by MITRE
Buffer overflow in internal string handling routines of xinetd before 2.1.8.8 allows remote attackers to execute arbitrary commands via a length argument of zero or less, which disables the length check.
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Analysis
by VulDB Data Team • 06/04/2018
The vulnerability identified as CVE-2001-0825 represents a critical buffer overflow flaw within the xinetd service daemon that was prevalent in versions prior to 2.1.8.8. This issue resides in the internal string handling routines of xinetd, which is a widely deployed super-server daemon responsible for managing network services by listening on specific ports and spawning appropriate service processes upon client connections. The vulnerability specifically targets the way xinetd processes string arguments during service initialization and configuration, creating a scenario where malicious input can lead to arbitrary code execution on the affected system.
The technical exploitation of this vulnerability hinges on the manipulation of length arguments within string processing functions. When an attacker provides a length argument that is zero or less, the validation logic within xinetd's internal routines becomes disabled, effectively bypassing the normal bounds checking mechanisms. This flaw constitutes a classic buffer overflow condition where the application fails to properly validate input parameters before processing them, allowing an attacker to overwrite adjacent memory locations. The vulnerability is categorized under CWE-121 as a stack-based buffer overflow, where insufficient boundary checking enables memory corruption that can be leveraged for privilege escalation and code execution.
The operational impact of this vulnerability extends beyond simple service disruption, as it provides remote attackers with the capability to execute arbitrary commands with the privileges of the xinetd process, typically running with elevated permissions. Since xinetd manages multiple network services and often runs with root privileges, successful exploitation can lead to complete system compromise. Attackers can leverage this vulnerability to gain unauthorized access to systems, install backdoors, modify system files, or establish persistent access. The vulnerability is particularly dangerous because it requires minimal input to trigger and can be exploited remotely without authentication, making it a prime target for automated attacks and exploit kits.
Mitigation strategies for CVE-2001-0825 focus primarily on immediate patching and system hardening measures. The most effective solution involves upgrading to xinetd version 2.1.8.8 or later, which includes proper input validation and bounds checking for string handling routines. Organizations should also implement network segmentation and access control measures to limit exposure, including restricting access to xinetd-managed services and employing firewall rules to block unnecessary ports. Additionally, system administrators should consider implementing intrusion detection systems to monitor for exploitation attempts and maintain regular security audits of service configurations. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in system design, aligning with ATT&CK technique T1068 which covers exploitation for privilege escalation and T1059 for command and scripting interpreter usage. Security professionals should also consider implementing application-level firewalls and monitoring for anomalous string processing behavior as part of their defensive strategies.