CVE-2004-1485 in InetUtils
Summary
by MITRE
Buffer overflow in the TFTP client in InetUtils 1.4.2 allows remote malicious DNS servers to execute arbitrary code via a large DNS response that is handled by the gethostbyname function.
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Analysis
by VulDB Data Team • 07/15/2017
The vulnerability identified as CVE-2004-1485 represents a critical buffer overflow flaw within the Trivial File Transfer Protocol client implementation of InetUtils version 1.4.2. This security weakness specifically manifests when the TFTP client processes DNS responses through the gethostbyname function, creating an exploitable condition that can be leveraged by remote attackers. The vulnerability stems from insufficient input validation and bounds checking within the DNS response handling mechanism, allowing malicious actors to craft oversized DNS replies that exceed the allocated buffer space. This particular flaw exists in the client-side implementation of network services and demonstrates a classic example of unsafe string handling in network applications. The issue is particularly concerning because it operates at the network level where attackers can manipulate DNS responses to exploit the vulnerability without requiring local access to the target system.
The technical exploitation of this buffer overflow occurs when the TFTP client receives a DNS response that contains an unusually large amount of data in its response fields. When the gethostbyname function processes this oversized response, it fails to properly validate the length of the incoming data against the buffer boundaries allocated for hostname resolution. This results in memory corruption where the excess data overflows into adjacent memory locations, potentially overwriting critical program state information including return addresses and function pointers. The vulnerability classifies as a CWE-121 stack-based buffer overflow, which is a well-documented weakness in software development practices where insufficient bounds checking allows attackers to overwrite stack memory. The attack vector is particularly dangerous because it can be executed remotely through DNS servers that are either compromised or maliciously configured to deliver oversized responses. The specific nature of the gethostbyname function usage makes this particularly concerning as it is a standard network resolution function that applications frequently rely upon, amplifying the potential impact across multiple systems.
The operational impact of this vulnerability extends beyond simple code execution, as it can potentially lead to complete system compromise and unauthorized access to network resources. When successfully exploited, the buffer overflow can allow remote attackers to execute arbitrary code with the privileges of the TFTP client process, which typically runs with system-level permissions. This could result in unauthorized data access, system infiltration, and potential lateral movement within network environments where TFTP clients are deployed. The vulnerability affects systems running InetUtils 1.4.2 and any applications that utilize the vulnerable gethostbyname function for DNS resolution. Network administrators should be particularly concerned about systems that have TFTP clients enabled and are connected to untrusted networks or DNS servers, as these configurations create the ideal conditions for exploitation. The attack can be automated and does not require specialized knowledge of the target system, making it particularly dangerous in environments where network security is not properly enforced.
Mitigation strategies for CVE-2004-1485 should prioritize immediate patching of affected InetUtils installations to version 1.4.3 or later, which contains the necessary buffer overflow protections and input validation improvements. Network administrators should implement DNS security measures including DNSSEC validation and monitoring for suspicious DNS responses that may indicate attempts to exploit this vulnerability. The implementation of network segmentation and access controls can help limit the potential impact of successful exploitation attempts by restricting access to TFTP services and related network resources. Additionally, system hardening measures such as disabling unnecessary TFTP client functionality, implementing proper input validation at network boundaries, and regular security auditing of network services can significantly reduce the attack surface. From an operational security perspective, organizations should establish monitoring procedures to detect unusual DNS traffic patterns and implement intrusion detection systems that can identify potential exploitation attempts. The vulnerability also highlights the importance of adhering to secure coding practices and following the ATT&CK framework's recommendations for preventing buffer overflow attacks through proper bounds checking and memory management techniques. Organizations should conduct regular vulnerability assessments to identify and remediate similar issues in other network utilities and applications that may be susceptible to similar exploitation methods.