CVE-2007-1933 in PcP-Guestbook
Summary
by MITRE
Multiple directory traversal vulnerabilities in PcP-Guestbook (PcP-Book) 3.0 allow remote attackers to include and execute arbitrary local files via a .. (dot dot) in the lang parameter to (1) index.php, (2) gb.php, or (3) faq.php.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 11/03/2025
The vulnerability identified as CVE-2007-1933 represents a critical directory traversal flaw affecting PcP-Guestbook version 3.0, a web-based guestbook application that was widely deployed in the mid-2000s era. This vulnerability stems from inadequate input validation mechanisms within the application's core scripting files, specifically targeting the lang parameter which is used to determine language localization files. The flaw allows remote attackers to manipulate file inclusion paths through the use of directory traversal sequences such as .. (dot dot) to navigate outside the intended directory structure and access arbitrary local files on the server. The vulnerability impacts three primary application endpoints including index.php, gb.php, and faq.php, each serving different functional purposes within the guestbook system. This weakness creates a pathway for attackers to potentially access sensitive system files, configuration data, or even execute malicious code on the vulnerable server. The vulnerability aligns with CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. These attacks exploit the fundamental principle that web applications should restrict access to files outside their intended scope, particularly when user input directly influences file system operations. The attack vector operates through the manipulation of the lang parameter where an attacker can submit crafted input such as ../../etc/passwd or similar directory traversal sequences to access files beyond the web root directory.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable complete system compromise. When an attacker successfully exploits this directory traversal vulnerability, they can access not only configuration files that may contain database credentials or other sensitive information but also system files that could reveal the underlying operating system configuration. The ability to include arbitrary local files opens the door for remote code execution if the application is configured to execute included files as PHP scripts or similar server-side technologies. This vulnerability specifically affects the guestbook application's language selection functionality, where the application dynamically includes language-specific files based on user input without proper sanitization. The exploitation process typically involves constructing malicious URLs that pass the directory traversal sequences to the vulnerable parameters, allowing the application to process these requests and return the contents of targeted system files or potentially execute code. The vulnerability demonstrates a classic lack of input validation and proper file access controls that were common in web applications of that era, when security practices were less mature and comprehensive.
Mitigation strategies for CVE-2007-1933 must address the core issue of improper input validation and implement robust access controls for file inclusion operations. The primary remediation involves implementing strict input validation and sanitization for all user-supplied parameters, particularly those used in file system operations. Applications should employ whitelisting approaches where only predefined, safe language files are permitted for inclusion rather than allowing arbitrary user input to determine file paths. The implementation of proper directory restrictions and absolute path resolution techniques can prevent attackers from navigating outside intended directories. Additionally, the application should be configured to use secure file inclusion methods that do not rely on user input to determine file paths. Security practitioners should also consider implementing web application firewalls that can detect and block suspicious directory traversal patterns, as well as conduct regular security audits to identify similar vulnerabilities in legacy applications. The vulnerability also highlights the importance of keeping web applications updated and patched, as this particular flaw was present in version 3.0 and likely addressed in subsequent releases. Organizations should implement comprehensive security testing procedures including dynamic application security testing and static code analysis to identify similar path traversal vulnerabilities. This vulnerability demonstrates the necessity of following security best practices such as the principle of least privilege, where applications should only have access to the minimum file system resources necessary for their operation. The attack model for this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, specifically focusing on the exploitation of file inclusion vulnerabilities to achieve remote code execution. Given the age of this vulnerability, it serves as a reminder of the critical importance of maintaining up-to-date security practices and the potential for legacy applications to harbor dangerous vulnerabilities that can be exploited by modern attack frameworks.