CVE-2003-0431 in Ethereal
Summary
by MITRE
The tvb_get_nstringz0 function in Ethereal 0.9.12 and earlier does not properly handle a zero-length buffer size, with unknown consequences.
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Analysis
by VulDB Data Team • 05/28/2019
The vulnerability identified as CVE-2003-0431 resides within the tvb_get_nstringz0 function of Ethereal version 0.9.12 and earlier, representing a critical flaw in network protocol analysis software that could potentially lead to arbitrary code execution or system compromise. This function serves as a crucial component in Ethereal's packet dissection capabilities, responsible for extracting null-terminated strings from captured network data. The flaw manifests when the function receives a zero-length buffer size parameter, which should theoretically be handled gracefully but instead creates unpredictable behavior within the application's memory management systems.
The technical implementation of this vulnerability stems from inadequate input validation within the tvb_get_nstringz0 function, which fails to properly sanitize or reject zero-length buffer size arguments. This specific condition creates a scenario where the function attempts to process memory operations without proper boundary checks, leading to potential buffer underflow or overflow conditions. The vulnerability aligns with CWE-129, which addresses improper validation of array index or string length, and represents a classic example of unchecked buffer access that can be exploited by malicious actors to manipulate memory structures. When Ethereal processes malformed network packets containing zero-length string specifications, the application's memory management becomes unpredictable, potentially allowing attackers to inject malicious code or cause application crashes.
The operational impact of this vulnerability extends beyond simple application instability, as it presents a significant risk to network security monitoring operations. Ethereal, now known as Wireshark, serves as a critical tool for network administrators and security professionals who rely on its accurate packet analysis capabilities. If exploited, this vulnerability could allow remote attackers to execute arbitrary code on systems running vulnerable versions of Ethereal, effectively compromising the security monitoring infrastructure. The unknown consequences mentioned in the original description indicate that the exact exploitation vectors and payloads remain undetermined, making this vulnerability particularly dangerous as it could potentially be weaponized in ways not yet discovered by the security community. Attackers could craft specially malformed network traffic that, when analyzed by vulnerable Ethereal installations, would trigger the buffer handling flaw and enable remote code execution or denial of service conditions.
Mitigation strategies for CVE-2003-0431 primarily focus on immediate software updates and version upgrades to patched versions of Ethereal or its successor Wireshark. Organizations utilizing this tool should prioritize upgrading to versions that address the buffer handling flaw in tvb_get_nstringz0 function, as this represents the most effective defense against exploitation. Additionally, network administrators should implement proper input validation and sanitization measures when processing network traffic, particularly in environments where Ethereal or Wireshark may be used for security monitoring. The vulnerability demonstrates the importance of robust input validation and proper boundary checking in network analysis tools, as highlighted by ATT&CK technique T1059.007 for command and scripting interpreter. System administrators should also consider implementing network segmentation and access controls to limit exposure of vulnerable systems and reduce the attack surface available to potential adversaries. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of vulnerable software installations within the network infrastructure.