CVE-2008-2836 in WebCalendar
Summary
by MITRE
PHP remote file inclusion vulnerability in send_reminders.php in WebCalendar 1.0.4 allows remote attackers to execute arbitrary PHP code via a URL in the includedir parameter and a 0 value for the noSet parameter, a different vector than CVE-2007-1483.
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Analysis
by VulDB Data Team • 10/28/2024
The vulnerability identified as CVE-2008-2836 represents a critical remote file inclusion flaw in WebCalendar 1.0.4 that specifically affects the send_reminders.php script. This vulnerability operates through a sophisticated attack vector that leverages parameter manipulation to achieve arbitrary code execution on the target system. The flaw manifests when the application processes the includedir parameter without proper validation, creating an opportunity for malicious actors to inject and execute arbitrary PHP code remotely. The vulnerability differs from CVE-2007-1483 in its attack methodology, specifically utilizing a 0 value for the noSet parameter to establish the execution path, making it a distinct but equally dangerous threat vector.
This vulnerability falls under the CWE-88 category of Improper Neutralization of Argument Delimiters in a Command, which is classified as a command injection weakness that can be exploited to execute arbitrary commands on the target system. The technical flaw resides in the application's failure to properly sanitize user input parameters, particularly the includedir parameter that should have been validated against malicious content. The vulnerability's exploitation requires a precise combination of parameters including the specific 0 value for noSet parameter, which demonstrates the sophisticated nature of the attack vector. The flaw essentially allows an attacker to manipulate the include mechanism of PHP to load and execute remote files, bypassing normal security controls and access restrictions.
The operational impact of this vulnerability is severe and potentially catastrophic for organizations using WebCalendar 1.0.4. Attackers can leverage this vulnerability to execute arbitrary code on the web server, potentially leading to complete system compromise, data exfiltration, and persistent backdoor access. The remote nature of the exploit means that attackers can target vulnerable systems from anywhere on the internet without requiring physical access or prior authentication. This vulnerability can be exploited to establish command and control channels, deploy additional malware, or use the compromised system as a launching point for further attacks within the network infrastructure. The lack of proper input validation creates an open door for attackers to execute malicious payloads that could include web shells, rootkits, or other persistence mechanisms.
Mitigation strategies for this vulnerability should focus on immediate patching of the WebCalendar application to the latest secure version that addresses this specific flaw. Organizations should implement proper input validation and sanitization for all user-supplied parameters, particularly those used in include or require statements within PHP applications. The implementation of a web application firewall can provide additional protection by detecting and blocking malicious patterns associated with remote file inclusion attacks. Security configurations should enforce the use of absolute paths for include statements and disable remote file inclusion capabilities in PHP configuration settings. Regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other applications. The ATT&CK framework categorizes this vulnerability under T1190 - Exploit Public-Facing Application, emphasizing the need for proper application hardening and network segmentation to limit the potential impact of such exploits. Additionally, implementing principle of least privilege for web application accounts and regular security monitoring can help detect and respond to exploitation attempts before they can cause significant damage to the organization's infrastructure and data assets.