CVE-2004-0634 in Ethereal
Summary
by MITRE
The SMB SID snooping capability in Ethereal 0.9.15 to 0.10.4 allows remote attackers to cause a denial of service (process crash) via a handle without a policy name, which causes a null dereference.
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Analysis
by VulDB Data Team • 12/16/2024
The vulnerability described in CVE-2004-0634 represents a critical denial of service flaw within Ethereal network protocol analyzer version 0.9.15 through 0.10.4. This issue specifically affects the SMB (Server Message Block) protocol parsing functionality that Ethereal employs to analyze network traffic. The vulnerability stems from inadequate input validation and error handling within the SMB SID snooping feature, which is designed to extract security identifiers from SMB network communications. When Ethereal encounters a malformed SMB packet containing a handle without a policy name, the application fails to properly handle this edge case, leading to a null pointer dereference that ultimately crashes the application process.
The technical root cause of this vulnerability lies in CWE-476, which identifies null pointer dereference as a fundamental programming error. In the context of Ethereal's SMB parsing code, when processing SMB traffic, the software attempts to access memory locations that have not been properly initialized or validated. This occurs specifically when handling SMB handles that lack associated policy names, a condition that can arise during normal network operations or when malicious actors craft specially crafted packets to exploit this weakness. The absence of proper null checks before dereferencing pointers causes the application to crash with a segmentation fault, effectively rendering the network analysis tool unavailable for legitimate use.
From an operational impact perspective, this vulnerability creates significant security concerns for network administrators who rely on Ethereal for monitoring and analyzing SMB traffic within their networks. The denial of service condition means that an attacker positioned on the same network segment can easily disrupt network monitoring capabilities by sending a single malicious SMB packet. This vulnerability directly maps to ATT&CK technique T1498, which covers network denial of service attacks, and can be leveraged as part of broader reconnaissance or disruption campaigns. The impact extends beyond simple service interruption, as it compromises the integrity of network monitoring operations that are crucial for detecting other potential security incidents.
The exploitation of this vulnerability requires minimal technical expertise, making it particularly dangerous in environments where network monitoring tools are widely deployed. Network administrators using affected versions of Ethereal should consider immediate mitigation strategies, including upgrading to patched versions of the software or implementing network segmentation to isolate critical monitoring infrastructure. The vulnerability also highlights the importance of proper input validation and defensive programming practices in network security tools, as the issue could have been prevented through comprehensive error handling and null pointer checks. Organizations should also consider implementing additional monitoring for unusual network traffic patterns that might indicate exploitation attempts, as the crash behavior can serve as an indicator of potential compromise attempts.