CVE-2006-3631 in Wireshark
Summary
by MITRE
Unspecified vulnerability in the SSH dissector in Wireshark (aka Ethereal) 0.9.10 to 0.99.0 allows remote attackers to cause a denial of service (infinite loop) via unknown attack vectors.
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Analysis
by VulDB Data Team • 06/23/2019
The vulnerability identified as CVE-2006-3631 represents a critical denial of service flaw within the SSH dissector component of Wireshark, formerly known as Ethereal, affecting versions ranging from 0.9.10 through 0.99.0. This issue manifests as an infinite loop condition that can be triggered remotely, potentially compromising the stability and availability of network analysis tools used by security professionals and network administrators worldwide. The SSH dissector is responsible for parsing and analyzing Secure Shell protocol traffic, making this vulnerability particularly concerning given the widespread use of SSH for secure remote access and management.
The technical nature of this vulnerability lies in the improper handling of malformed or unexpected SSH protocol data within the dissector module. When Wireshark processes network packets containing specially crafted SSH traffic, the dissector enters an infinite loop state where it continuously processes the same data without making forward progress. This behavior stems from inadequate input validation and error handling mechanisms within the SSH protocol parsing logic, creating a condition where the application becomes unresponsive and consumes excessive system resources. The vulnerability is classified under CWE-838, which deals with insufficient input validation, and represents a classic example of a resource exhaustion attack that can be executed without requiring authentication or specialized privileges.
The operational impact of this vulnerability extends beyond simple service disruption, as it can severely compromise the effectiveness of network security monitoring and incident response activities. Network administrators who rely on Wireshark for traffic analysis, forensic investigations, and security auditing may find their analysis tools become completely unresponsive when processing maliciously crafted network traffic. This creates a cascading effect where legitimate network monitoring activities are disrupted, potentially masking actual security incidents or preventing timely detection of network anomalies. The vulnerability also impacts the broader cybersecurity ecosystem since many security professionals depend on Wireshark for their daily operations, making this a significant concern for organizations that require continuous network visibility and analysis capabilities.
Mitigation strategies for CVE-2006-3631 primarily involve immediate software updates to versions that contain patches addressing the infinite loop condition in the SSH dissector. Users should upgrade to Wireshark version 0.99.1 or later, where the vulnerability has been resolved through enhanced input validation and improved error handling mechanisms. Additionally, network administrators should implement network segmentation and traffic filtering to prevent potentially malicious SSH traffic from reaching systems running vulnerable versions of Wireshark. The remediation process should also include comprehensive testing of updated software in controlled environments before deployment to ensure compatibility with existing network monitoring workflows. Organizations may also consider implementing alternative network analysis tools or maintaining multiple versions of analysis software to provide redundancy in case of similar vulnerabilities. From an ATT&CK perspective, this vulnerability aligns with technique T1499.004 for network denial of service and demonstrates the importance of maintaining up-to-date network security tools to prevent exploitation of known vulnerabilities.