CVE-2003-0081 in Ethereal
Summary
by MITRE
Format string vulnerability in packet-socks.c of the SOCKS dissector for Ethereal 0.8.7 through 0.9.9 allows remote attackers to execute arbitrary code via SOCKS packets containing format string specifiers.
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Analysis
by VulDB Data Team • 05/28/2019
The vulnerability identified as CVE-2003-0081 represents a critical format string vulnerability within the SOCKS dissector component of Ethereal network protocol analyzer version 0.8.7 through 0.9.9. This flaw resides in the packet-socks.c file and demonstrates a classic security weakness that has been documented in the cybersecurity community for decades. The vulnerability arises from improper input validation and handling of user-supplied data within the network packet parsing logic, specifically when processing SOCKS protocol packets that contain format string specifiers.
The technical flaw manifests when the SOCKS dissector processes incoming network packets without properly sanitizing or escaping format string specifiers that may be embedded within the SOCKS protocol data. This creates an environment where maliciously crafted SOCKS packets can contain format specifiers such as %s, %d, or %x that are subsequently passed to vulnerable printf-style functions without proper formatting arguments. The vulnerability falls under CWE-134 which specifically addresses the use of format strings without proper validation, making it a well-documented and widely understood class of vulnerabilities in software security. When the application attempts to process these malformed packets, the format string specifiers are interpreted by the printf function as instructions for reading from memory locations, potentially leading to information disclosure, application crashes, or more critically, arbitrary code execution.
The operational impact of this vulnerability is severe and potentially catastrophic for systems running affected versions of Ethereal. Remote attackers can exploit this weakness to execute arbitrary code on the system running the network analyzer, effectively compromising the entire network monitoring infrastructure. This creates a significant attack surface where malicious actors can gain unauthorized access to sensitive network data, potentially leading to data breaches, network reconnaissance, and further lateral movement within the compromised environment. The vulnerability is particularly dangerous because it allows remote code execution without requiring authentication, making it an attractive target for attackers seeking to compromise network monitoring systems. From an attack framework perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1059.007 technique for command and scripting interpreter, specifically focusing on the exploitation of application-level vulnerabilities to achieve code execution. The impact extends beyond simple privilege escalation as the compromised network analyzer could provide attackers with detailed insights into network traffic patterns, potentially exposing sensitive communications and network architecture information.
The remediation for this vulnerability requires immediate patching of the Ethereal application to version 0.10.0 or later, which contains the necessary fixes for the format string vulnerability. Organizations should implement network segmentation and access controls to limit exposure of network monitoring systems to untrusted networks. Additionally, network administrators should consider implementing intrusion detection systems that can detect and alert on suspicious SOCKS protocol traffic patterns. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in network security implementations, where applications should never trust external input and should always sanitize all data before processing. Security teams should also conduct regular vulnerability assessments of network monitoring tools and ensure that all security patches are applied promptly to prevent exploitation of known vulnerabilities. This case study exemplifies why security-conscious development practices, including the use of secure coding standards and regular security testing, are essential components of any robust cybersecurity program.