CVE-2007-1435 in TFTP Server
Summary
by MITRE
Buffer overflow in D-Link TFTP Server 1.0 allows remote attackers to cause a denial of service (crash) via a long (1) GET or (2) PUT request, which triggers memory corruption. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 11/30/2024
The vulnerability identified as CVE-2007-1435 represents a critical buffer overflow flaw in the D-Link TFTP Server version 1.0 that exposes systems to remote exploitation. This issue specifically affects the Trivial File Transfer Protocol implementation within the D-Link firmware ecosystem, creating a pathway for malicious actors to disrupt service availability through carefully crafted network requests. The vulnerability operates at the network protocol level where the TFTP server fails to properly validate input lengths during file transfer operations, leading to memory corruption that ultimately results in system crash and denial of service conditions.
The technical exploitation of this buffer overflow occurs when remote attackers send malformed GET or PUT requests to the vulnerable TFTP server instance. These requests contain excessively long data payloads that exceed the allocated buffer space within the server's memory management structure. The D-Link TFTP Server 1.0 implementation does not perform adequate bounds checking or input validation before processing these requests, allowing attackers to overwrite adjacent memory locations. This memory corruption typically manifests as stack overflow conditions or heap corruption, causing the server process to terminate abruptly and resulting in complete service disruption for legitimate users attempting to access file transfer services.
From an operational impact perspective, this vulnerability creates significant security risks for organizations utilizing D-Link networking equipment in their infrastructure. The remote nature of the exploit means that attackers can initiate denial of service attacks from anywhere on the network without requiring local system access or authentication credentials. This makes the vulnerability particularly dangerous in enterprise environments where TFTP services may be used for firmware updates, configuration file transfers, or other critical network operations. The impact extends beyond simple service interruption as it can potentially disrupt network management functions, automated deployment processes, and administrative access to network devices that depend on TFTP functionality.
The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation in network services. From the MITRE ATT&CK framework perspective, this issue maps to the T1499.004 technique for network denial of service, where adversaries leverage protocol implementation flaws to disrupt availability. Organizations should implement immediate mitigations including network segmentation to isolate vulnerable TFTP servers, disabling unnecessary TFTP services where possible, and applying vendor patches or firmware updates when available. The lack of verified exploit code or detailed exploitation methodology in the original report suggests that this vulnerability may have been discovered through vulnerability research rather than active exploitation, but the potential for serious service disruption remains significant for affected installations.
The broader implications of this vulnerability highlight the importance of proper input validation and memory management in network services. Many embedded network devices suffer from similar issues due to limited resources and rushed development cycles, making them prime targets for exploitation. System administrators should conduct comprehensive inventory audits to identify all instances of D-Link TFTP servers and other vulnerable network services within their environments, implementing monitoring solutions to detect unusual traffic patterns that may indicate exploitation attempts. Additionally, organizations should consider implementing network access controls to restrict access to TFTP services to only trusted network segments and establish incident response procedures for handling potential exploitation attempts. The vulnerability demonstrates that even seemingly simple protocol implementations can contain critical security flaws that require careful attention to input handling and memory management practices.