CVE-2018-10389 in TFTP Server MT
Summary
by MITRE
Format string vulnerability in the logMess function in TFTP Server MT 1.65 and earlier allows remote attackers to perform a denial of service or execute arbitrary code via format string sequences in a TFTP error packet.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 03/16/2024
The vulnerability identified as CVE-2018-10389 represents a critical format string vulnerability within the TFTP Server MT version 1.65 and earlier implementations. This flaw exists within the logMess function which processes error packets during TFTP operations. The vulnerability stems from improper input validation and handling of format specifiers within the logging mechanism, creating a path for remote attackers to manipulate the program's execution flow through crafted error packets.
The technical exploitation of this vulnerability occurs when a remote attacker sends a specially crafted TFTP error packet containing format string sequences to the vulnerable server. The logMess function fails to properly sanitize these inputs before passing them to printf or similar formatting functions, allowing attackers to inject format specifiers that can trigger various malicious behaviors. This vulnerability falls under CWE-134 which specifically addresses the use of user-supplied format strings in functions like printf, sprintf, and related formatting functions. The attack vector is particularly dangerous as it can be executed remotely without authentication requirements, making it accessible to any network-connected attacker.
The operational impact of this vulnerability extends beyond simple denial of service conditions to include potential arbitrary code execution on the affected system. When attackers successfully exploit the format string vulnerability, they can manipulate the program's memory layout, overwrite critical function pointers, or inject malicious code into the server process. This capability allows for complete system compromise, enabling attackers to establish persistent access, escalate privileges, or deploy additional malware. The vulnerability affects the fundamental integrity of the TFTP server's logging mechanism and can be leveraged to disrupt network operations through denial of service while simultaneously providing a backdoor for further exploitation.
Mitigation strategies for CVE-2018-10389 should prioritize immediate patching of the affected TFTP Server MT versions to address the format string vulnerability in the logMess function. Organizations should implement network segmentation and access controls to limit exposure of TFTP servers to untrusted networks, while also deploying intrusion detection systems to monitor for suspicious TFTP error packet patterns. Security teams should conduct comprehensive vulnerability assessments to identify all instances of the affected software and ensure proper input validation is implemented in logging functions. The ATT&CK framework categorizes this vulnerability under T1059 (Command and Scripting Interpreter) and T1105 (Remote File Copy) as exploitation can lead to command execution and file transfer capabilities. Additionally, implementing proper network monitoring and log analysis procedures can help detect exploitation attempts and provide early warning of potential attacks targeting this specific vulnerability.