CVE-2001-1557 in AIX
Summary
by MITRE
Buffer overflow in ftpd in IBM AIX 4.3 and 5.1 allows attackers to gain privileges.
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Analysis
by VulDB Data Team • 06/27/2021
The vulnerability identified as CVE-2001-1557 represents a critical buffer overflow flaw within the ftpd daemon component of IBM AIX operating systems version 4.3 and 5.1. This issue resides in the file transfer protocol server implementation and demonstrates a classic security weakness that can be exploited to escalate privileges from regular user level to root access. The buffer overflow occurs when the ftpd service processes certain malformed input data during authentication or command execution phases, creating an opportunity for malicious actors to manipulate memory structures and execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability stems from inadequate input validation and buffer management within the ftpd service code. When the daemon receives specific command sequences or data payloads that exceed predetermined buffer limits, it fails to properly handle the overflow condition, leading to memory corruption that can be leveraged by attackers. This flaw operates under CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations, potentially including return addresses or control data structures. The vulnerability specifically affects the authentication and command processing phases of the ftpd service, making it particularly dangerous as it can be exploited during normal user interactions with the file transfer protocol.
The operational impact of CVE-2001-1557 extends beyond simple privilege escalation to encompass potential system compromise and unauthorized access to sensitive data. Attackers exploiting this vulnerability can gain root-level access to affected AIX systems, enabling them to modify system files, install backdoors, exfiltrate confidential information, or establish persistent access points. This type of privilege escalation vulnerability is particularly concerning in enterprise environments where AIX servers often host critical business applications and data repositories. The attack vector typically involves connecting to the FTP service and sending carefully crafted commands that trigger the buffer overflow condition, making it possible for remote attackers to compromise systems without requiring physical access or prior authentication credentials.
Mitigation strategies for this vulnerability require immediate system patching and configuration hardening measures. IBM released security patches for AIX 4.3 and 5.1 that address the buffer overflow condition in the ftpd service by implementing proper input validation and buffer boundary checks. Organizations should prioritize applying these patches to all affected systems and consider disabling unnecessary FTP services when not required for business operations. Network segmentation and firewall rules can help limit exposure by restricting access to FTP ports from trusted networks only. Additionally, implementing intrusion detection systems that monitor for suspicious FTP command sequences and establishing regular security audits of system configurations aligns with ATT&CK framework techniques for defensive measures against privilege escalation attacks. The vulnerability also highlights the importance of maintaining up-to-date security patches and following secure coding practices to prevent similar buffer overflow conditions in other system components.