CVE-2003-0926 in Ethereal
Summary
by MITRE
Ethereal 0.9.15 and earlier, and Tethereal, allows remote attackers to cause a denial of service (crash) via certain malformed (1) ISAKMP or (2) MEGACO packets.
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Analysis
by VulDB Data Team • 06/12/2019
The vulnerability identified as CVE-2003-0926 represents a critical denial of service flaw affecting network protocol analysis tools that were widely used in enterprise and security environments during the early 2000s. This vulnerability specifically impacted both Ethereal version 0.9.15 and earlier releases, as well as its predecessor Tethereal, which served as the foundation for modern Wireshark packet analysis software. The flaw manifested when these tools processed specially crafted network packets that contained malformed ISAKMP (Internet Security Association and Key Management Protocol) or MEGACO (Media Gateway Control Protocol) data structures. These protocols are fundamental to secure communications and multimedia gateway control respectively, making the vulnerability particularly concerning for network security operations. The issue stems from inadequate input validation and error handling mechanisms within the packet parsing routines of these network analysis tools, creating a condition where malformed packet data could trigger unexpected behavior in the application's memory management subsystems.
The technical exploitation of this vulnerability occurs through the deliberate crafting of network packets that contain malformed ISAKMP or MEGACO headers and payload structures. When Ethereal or Tethereal encounters such malformed packets during network traffic capture and analysis, the software's packet parsing functions fail to properly handle the unexpected data formats. This failure typically results in memory corruption, buffer overflows, or invalid pointer dereferences within the application's processing pipeline. The specific nature of the vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read errors. These memory corruption vulnerabilities are particularly dangerous because they can be exploited to cause application crashes, potentially leading to complete system instability or service unavailability. The attack vector requires only the ability to transmit malicious network traffic to the system running the vulnerable software, making it accessible to remote attackers without requiring authentication or elevated privileges.
From an operational perspective, the impact of CVE-2003-0926 extends beyond simple service disruption to potentially compromise network monitoring capabilities that organizations rely upon for security operations and incident response. Network administrators and security analysts who depend on Ethereal or Tethereal for network troubleshooting, protocol analysis, and security monitoring would face significant operational challenges when encountering this vulnerability. The denial of service condition could occur during critical network events, such as security incidents, network troubleshooting sessions, or routine monitoring activities, leading to loss of network visibility and potential security gaps. This vulnerability particularly affects environments where these tools are used for continuous network monitoring, as any malicious actor could exploit the flaw to disrupt network analysis operations and potentially mask other security incidents. The flaw also demonstrates the broader category of software reliability issues that can affect security tools, as these applications are often expected to remain operational under all network conditions, including malicious traffic conditions.
Organizations should implement immediate mitigations including upgrading to patched versions of Ethereal or transitioning to Tethereal 0.9.16 and later releases that contain the necessary input validation fixes. The vulnerability highlights the importance of robust input validation and error handling in security tools, as these applications must be resilient to malformed network traffic to maintain operational integrity. System administrators should also consider implementing network segmentation and access controls to limit exposure to potentially malicious traffic, while maintaining multiple monitoring tools to ensure redundancy in case one tool becomes compromised. The incident underscores the need for comprehensive security testing of network analysis tools, particularly in environments where they process untrusted network data, and emphasizes the critical role of keeping security tools updated to address known vulnerabilities. Organizations should also review their incident response procedures to account for potential disruptions caused by such denial of service vulnerabilities in essential monitoring infrastructure, aligning with ATT&CK technique T1499 which covers network denial of service attacks against infrastructure components.