CVE-2005-0665 in John Bradley
Summary
by MITRE
Format string vulnerability in xv before 3.10a allows remote attackers to execute arbitrary code via format string specifiers in a filename.
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Analysis
by VulDB Data Team • 06/07/2019
The vulnerability identified as CVE-2005-0665 represents a critical format string flaw in the xv image viewer software prior to version 3.10a. This vulnerability exists within the application's handling of filename arguments, where the software fails to properly sanitize user-supplied input before using it in printf-style formatting operations. The xv application, widely used for viewing various image formats on unix-like systems, processes command line arguments containing filenames without adequate validation, creating an exploitable condition that can be leveraged by remote attackers.
The technical nature of this vulnerability stems from improper input validation within the filename processing logic of xv. When the application receives a filename argument containing format specifiers such as %s, %d, or other printf-style directives, it directly passes this unvalidated input to format string functions without proper sanitization. This behavior allows attackers to craft malicious filenames that contain format string specifiers, which when processed by the vulnerable application can lead to arbitrary code execution. The flaw operates under the common weakness identified as CWE-134, which specifically addresses the use of format strings with user-supplied data without proper validation or sanitization.
From an operational perspective, this vulnerability presents significant risk to systems running vulnerable versions of xv, particularly in environments where users might be exposed to untrusted image files or when the application is used in networked contexts. Attackers can exploit this vulnerability remotely by crafting specially formatted filenames that, when processed by the vulnerable xv application, can overwrite memory locations, execute arbitrary code, or cause denial of service conditions. The impact extends beyond simple code execution to potentially allow privilege escalation if the vulnerable application runs with elevated permissions, making it a particularly dangerous flaw in multi-user environments.
The exploitability of this vulnerability requires that the vulnerable application processes user-supplied filenames containing format specifiers, which can occur through various attack vectors including web-based file uploads, email attachments, or network file sharing scenarios. Security professionals should note that this vulnerability aligns with several tactics described in the ATT&CK framework under privilege escalation and code execution techniques. The vulnerability demonstrates how seemingly benign input processing functions can become attack surfaces when proper input validation is omitted, highlighting the importance of defensive programming practices and adherence to secure coding standards. Organizations should immediately upgrade to xv version 3.10a or later, which includes proper input sanitization measures to prevent format string exploitation, and implement additional monitoring for suspicious filename patterns in system logs to detect potential exploitation attempts.
The broader implications of this vulnerability extend to the general principles of secure software development, particularly emphasizing the need for robust input validation and the avoidance of dangerous functions such as sprintf, fprintf, and related format string operations with untrusted data. This flaw serves as a reminder that applications must always validate and sanitize user input before processing, especially when that input will be used in contexts where it might be interpreted as formatting directives rather than literal data. The vulnerability also underscores the importance of regular security updates and vulnerability assessments in maintaining system security posture, particularly for widely deployed applications that may not receive frequent updates from their developers.