CVE-2008-5968 in phpicalendar
Summary
by MITRE
Directory traversal vulnerability in print.php in PHP iCalendar 2.24 and earlier allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the cookie_language parameter in a phpicalendar_* cookie, a different vector than CVE-2006-1292.
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Analysis
by VulDB Data Team • 11/04/2024
The vulnerability identified as CVE-2008-5968 represents a directory traversal flaw in PHP iCalendar version 2.24 and earlier, specifically affecting the print.php component. This issue arises from insufficient input validation when processing the cookie_language parameter within the phpicalendar_* cookie, creating an opportunity for remote attackers to manipulate file inclusion mechanisms. The vulnerability operates through a path traversal attack vector where malicious actors can exploit the .. (dot dot) sequence to navigate outside the intended directory boundaries and access arbitrary local files on the server. Unlike similar vulnerabilities such as CVE-2006-1292, this particular flaw manifests through cookie manipulation rather than direct parameter injection, making it more subtle and potentially harder to detect through standard network monitoring.
The technical implementation of this vulnerability stems from the application's failure to properly sanitize user-supplied input from the cookie_language parameter before using it in file inclusion operations. When PHP iCalendar processes the phpicalendar_* cookie containing the cookie_language value, it directly incorporates this unvalidated input into file path construction without adequate sanitization or validation mechanisms. This allows an attacker to craft malicious cookie values containing sequences like ../../etc/passwd or similar path traversal patterns that can access sensitive system files. The vulnerability is classified under CWE-22 as a "Path Traversal" attack, specifically demonstrating improper input validation in file access operations. The flaw operates at the application layer and can be exploited remotely without requiring authentication, making it particularly dangerous in web environments where the application is publicly accessible.
The operational impact of CVE-2008-5968 extends beyond simple information disclosure, as successful exploitation can lead to complete system compromise. Attackers can potentially execute arbitrary code by including and executing local files, which may include system configuration files, database credentials, or even malicious scripts that could establish persistent backdoors. The vulnerability enables attackers to access sensitive files such as password hashes, configuration files containing database credentials, and system logs that could provide further attack vectors. In addition to direct file access, this vulnerability can facilitate privilege escalation attacks where attackers gain access to system resources they should not normally have access to. The attack surface is particularly concerning in shared hosting environments or applications where multiple users interact with the same system, as exploitation could potentially allow attackers to access data from other users or applications running on the same server.
Mitigation strategies for CVE-2008-5968 should focus on input validation and proper parameter sanitization within the application code. The most effective immediate solution involves implementing strict input validation for the cookie_language parameter, rejecting any input containing path traversal sequences such as .. or /../. Organizations should implement a whitelist approach for acceptable language values and ensure that all user-supplied input undergoes proper sanitization before being used in file operations. The recommended approach aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as this vulnerability can enable attackers to execute arbitrary code through file inclusion. Additionally, implementing proper access controls and file permission settings can limit the damage from successful exploitation attempts. Regular security updates and patches should be deployed immediately upon availability, as this vulnerability has been known since 2008 and has been addressed in subsequent versions of PHP iCalendar. Organizations should also consider implementing web application firewalls that can detect and block suspicious cookie values containing path traversal patterns, providing an additional layer of protection against such attacks.