CVE-2006-1940 in Ethereal
Summary
by MITRE
Unspecified vulnerability in Ethereal 0.10.4 up to 0.10.14 allows remote attackers to cause a denial of service (abort) via the SNDCP dissector.
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Analysis
by VulDB Data Team • 06/17/2019
The vulnerability identified as CVE-2006-1940 represents a critical denial of service weakness within the Ethereal network protocol analyzer version 0.10.4 through 0.10.14. This issue specifically affects the SNDCP dissector component which is responsible for decoding the Subnetwork Dependent Convergence Protocol used in GSM networks. The flaw manifests when the software processes malformed or specially crafted SNDCP packets, causing the application to abruptly terminate or abort its operation. This type of vulnerability falls under the category of improper input validation as defined by CWE-20, where the system fails to properly handle unexpected or malformed input data. The SNDCP dissector in Ethereal was designed to analyze and display network traffic for diagnostic purposes, but it did not adequately validate the structure and content of incoming packets before processing them.
The operational impact of this vulnerability extends beyond simple service interruption as it affects the reliability and availability of network monitoring operations. When an attacker successfully exploits this weakness, they can cause Ethereal to crash, forcing network administrators to restart the application and potentially lose valuable network traffic analysis data. This denial of service condition directly impacts the network security monitoring capabilities of organizations relying on Ethereal for network traffic inspection. The vulnerability is particularly concerning in environments where continuous network monitoring is essential for security operations, as the crash can occur without warning and may go unnoticed until network anomalies are detected. The attack vector is remote, meaning that an attacker does not need physical access to the system, and can exploit the vulnerability from anywhere on the network by simply sending specially crafted SNDCP packets to the target system running Ethereal. This aligns with ATT&CK technique T1499.004 which covers network denial of service attacks.
The technical nature of this vulnerability demonstrates a classic buffer over-read or improper state handling issue within the dissector implementation. When Ethereal encounters malformed SNDCP packets, the dissector fails to properly validate packet headers or structure before attempting to parse the data, leading to an abnormal termination. This behavior can be categorized as a software fault that violates the principle of graceful error handling, where applications should be designed to recover from unexpected input rather than simply aborting. The vulnerability represents a failure in defensive programming practices and proper error handling mechanisms that should be implemented in network protocol analyzers to maintain system stability. Organizations using Ethereal for network security monitoring should be particularly concerned as this vulnerability could be exploited by malicious actors to disrupt network analysis operations, potentially masking other security incidents or attacks. The remediation approach requires updating to a patched version of Ethereal where the SNDCP dissector has been properly hardened against malformed input, or implementing network segmentation to isolate systems running the vulnerable software. Additionally, network administrators should consider implementing intrusion detection systems that can identify and block suspicious SNDCP traffic patterns that may indicate exploitation attempts.