CVE-2001-0755 in Linux
Summary
by MITRE
Buffer overflow in ftp daemon (ftpd) 6.2 in Debian GNU/Linux allows attackers to cause a denial of service and possibly execute arbitrary code via a long SITE command.
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Analysis
by VulDB Data Team • 05/08/2017
The vulnerability identified as CVE-2001-0755 represents a critical buffer overflow flaw within the ftp daemon component of Debian GNU/Linux version 6.2. This issue specifically affects the handling of SITE commands within the ftpd service, creating a significant security risk that can be exploited by malicious actors to compromise system integrity and availability. The vulnerability stems from inadequate input validation and memory management within the ftp daemon's command processing routine, where the system fails to properly check the length of incoming SITE command parameters before attempting to store them in fixed-size buffers.
The technical nature of this buffer overflow manifests when an attacker crafts a malicious SITE command containing excessive data input that exceeds the allocated buffer space. This overflow condition occurs during the processing of the SITE command, which is a standard extension command used in ftp protocol implementations for various administrative functions. The flaw allows the attacker to overwrite adjacent memory locations, potentially corrupting program execution flow and creating opportunities for arbitrary code execution. According to CWE classification, this vulnerability maps to CWE-121 which describes heap-based buffer overflow conditions, while the ATT&CK framework categorizes this under privilege escalation and execution techniques. The vulnerability exists because the ftp daemon does not implement proper bounds checking on user-supplied input, allowing memory corruption that can be leveraged for malicious purposes.
The operational impact of this vulnerability extends beyond simple denial of service to include potential system compromise and unauthorized access. When exploited successfully, the buffer overflow can cause the ftp daemon process to crash, leading to denial of service for legitimate users, but more critically, it can allow attackers to execute arbitrary code with the privileges of the ftp daemon process. This typically translates to elevated system access that could enable further exploitation within the network environment. The vulnerability affects systems running Debian GNU/Linux 6.2 where the ftpd service is active, making it particularly dangerous in server environments where ftp services are commonly deployed. Attackers can leverage this weakness to gain persistent access to systems, potentially using it as a foothold for broader network infiltration activities.
Mitigation strategies for CVE-2001-0755 require immediate system patching and configuration hardening measures. The most effective approach involves updating the ftp daemon to a patched version that implements proper input validation and buffer boundary checking for SITE command processing. System administrators should disable unnecessary ftp services and implement network segmentation to limit exposure. Additional protective measures include configuring firewalls to restrict ftp access to trusted networks, implementing intrusion detection systems to monitor for suspicious SITE command patterns, and conducting regular security audits of ftp configurations. The vulnerability demonstrates the importance of input validation practices and proper memory management in network services, aligning with security best practices outlined in various industry standards including those from the Center for Internet Security and NIST guidelines for secure system configuration. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates and prevent similar vulnerabilities from being exploited in their environments.