CVE-2002-0276 in Ettercap
Summary
by MITRE
Buffer overflow in various decoders in Ettercap 0.6.3.1 and earlier, when running on networks with an MTU greater than 2000, allows remote attackers to execute arbitrary code via large packets.
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Analysis
by VulDB Data Team • 12/07/2024
The vulnerability identified as CVE-2002-0276 represents a critical buffer overflow flaw affecting Ettercap version 0.6.3.1 and earlier releases. This security weakness manifests specifically within the network protocol decoders of Ettercap, a powerful network sniffer and packet manipulator tool widely used for network monitoring and security auditing. The flaw becomes particularly exploitable when Ettercap operates on networks utilizing maximum transmission unit sizes exceeding 2000 bytes, creating a dangerous condition where malformed network packets can trigger memory corruption. The vulnerability stems from inadequate input validation and bounds checking within the packet processing routines that handle network traffic analysis and interception.
The technical implementation of this buffer overflow occurs when Ettercap processes network packets that exceed the expected buffer size limits during the decoding phase. When the MTU exceeds 2000 bytes, the decoders fail to properly validate packet sizes before copying data into fixed-size buffers, allowing attackers to craft specially designed packets that overwrite adjacent memory locations. This memory corruption can potentially overwrite critical program variables, return addresses, or function pointers, enabling remote attackers to execute arbitrary code with the privileges of the Ettercap process. The vulnerability is particularly concerning because it can be exploited remotely without requiring authentication, making it accessible to any attacker who can send malicious packets to the target system.
The operational impact of CVE-2002-0276 extends beyond simple code execution, as it fundamentally compromises the integrity and confidentiality of network monitoring operations. When exploited successfully, the vulnerability allows attackers to gain unauthorized access to the target system, potentially enabling them to intercept sensitive network communications, manipulate traffic flows, or establish persistent backdoors. This makes the vulnerability particularly dangerous in environments where Ettercap is used for security monitoring, penetration testing, or network analysis, as it could allow adversaries to compromise the very tools designed to protect network security. The remote exploit capability means that attackers do not need physical access to the target system or network, making the vulnerability extremely difficult to defend against through traditional network segmentation approaches.
The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and reflects patterns commonly found in network protocol parsing implementations. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including T1046 for network service scanning and T1059 for command and scripting interpreter usage. Organizations using Ettercap in production environments should prioritize immediate patching of affected versions, as no reliable workarounds exist for this specific buffer overflow condition. Network administrators should also implement additional monitoring and intrusion detection measures to detect potential exploitation attempts, while considering network segmentation strategies to limit the potential impact of successful attacks. The vulnerability highlights the critical importance of proper input validation in network protocol implementations and serves as a reminder of the security implications of buffer overflow conditions in network security tools.