CVE-2005-0959 in mtftpd
Summary
by MITRE
Buffer overflow in the mt_do_dir function in YepYep mtftpd 0.0.3 may allow attackers to execute arbitrary code via a long path.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 01/18/2025
The vulnerability identified as CVE-2005-0959 represents a critical buffer overflow flaw within the mtftpd 0.0.3 file transfer protocol server implementation. This specific weakness resides in the mt_do_dir function which handles directory listing operations, creating a potential entry point for malicious actors to gain unauthorized system control. The flaw manifests when the server processes directory paths that exceed predetermined buffer limits, allowing attackers to overwrite adjacent memory locations through carefully crafted long path inputs. Such buffer overflow conditions fall under the common weakness enumeration CWE-121, which specifically addresses stack-based buffer overflow vulnerabilities that occur when insufficient bounds checking permits data to be written beyond the allocated buffer boundaries. The operational impact of this vulnerability extends beyond simple denial of service scenarios, as the memory corruption can be exploited to execute arbitrary code with the privileges of the running service, potentially leading to complete system compromise. Attackers leveraging this vulnerability can manipulate the program execution flow by overwriting return addresses or function pointers in the call stack, enabling them to inject and execute malicious code within the target system's memory space. This type of exploitation aligns with the attack pattern described in the attack technique ATT&CK T1059.007 for command and scripting interpreter, where adversaries leverage buffer overflow conditions to gain code execution capabilities.
The technical nature of this vulnerability stems from improper input validation within the mtftpd server implementation, specifically failing to enforce adequate bounds checking on user-supplied path data during directory listing operations. When the mt_do_dir function processes directory requests, it likely uses a fixed-size buffer to store path information without sufficient validation of input length, creating a predictable overflow condition. This flaw demonstrates poor defensive programming practices that violate fundamental security principles of input sanitization and memory safety. The vulnerability is particularly concerning because it operates at the application layer within a network service, meaning that remote exploitation is possible without requiring local system access. The attack surface is further expanded by the fact that directory listing operations are common in file transfer protocols, making this vulnerability accessible through routine network interactions. The lack of proper stack canaries or other modern exploit mitigation techniques in the vulnerable version of mtftpd compounds the risk, as traditional exploitation methods become more viable. This vulnerability directly maps to the broader category of software security flaws categorized under CWE-787, which addresses out-of-bounds write conditions that can lead to arbitrary code execution. The exploitation process typically involves crafting a malicious path string that exceeds the buffer capacity, causing the overflow to overwrite critical program memory locations and redirect execution flow to attacker-controlled code.
Mitigation strategies for CVE-2005-0959 must address both the immediate vulnerability and broader security posture of affected systems. The primary recommendation involves updating to a patched version of mtftpd that implements proper bounds checking and input validation for directory path operations. System administrators should also implement network segmentation and access controls to limit exposure of vulnerable services to untrusted networks. Network-based mitigations can include implementing firewall rules that restrict access to the affected FTP service or employing intrusion detection systems that monitor for suspicious path length patterns. The implementation of modern exploit protection mechanisms such as stack canaries, address space layout randomization, and data execution prevention can significantly reduce the effectiveness of exploitation attempts. Additionally, input validation should be enforced at multiple layers of the application architecture, including application-level checks to ensure path lengths do not exceed safe thresholds. Organizations should also conduct comprehensive vulnerability assessments to identify other potentially vulnerable services or applications that may share similar buffer handling patterns. Regular security audits and code reviews focusing on memory management practices can help prevent similar vulnerabilities from being introduced in future implementations. The remediation process should include thorough testing to ensure that the patched version maintains expected functionality while eliminating the buffer overflow condition, following secure coding practices that align with industry standards for memory-safe programming.