CVE-2009-0820 in phpScheduleIt
Summary
by MITRE
Multiple eval injection vulnerabilities in phpScheduleIt before 1.2.11 allow remote attackers to execute arbitrary code via (1) the end_date parameter to reserve.php and (2) the start_date and end_date parameters to check.php. NOTE: the start_date/reserve.php vector is already covered by CVE-2008-6132.
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Analysis
by VulDB Data Team • 08/04/2025
The vulnerability described in CVE-2009-0820 represents a critical server-side code injection flaw in the phpScheduleIt application, a web-based scheduling system widely used for resource reservation management. This vulnerability affects versions prior to 1.2.11 and demonstrates the dangerous consequences of improper input validation and sanitization in web applications. The flaw specifically manifests through the exploitation of eval() function calls with unsanitized user input, creating a pathway for remote attackers to execute arbitrary code on the targeted server. The vulnerability impacts two distinct endpoints within the application's codebase, each presenting unique attack vectors that collectively amplify the overall risk.
The technical exploitation occurs through the manipulation of date parameters in two separate PHP scripts. In the reserve.php script, the end_date parameter is processed through an eval() function call without proper input validation, allowing attackers to inject malicious PHP code that gets executed during the reservation process. Similarly, the check.php script contains vulnerabilities in both start_date and end_date parameter handling, where user-supplied date values are directly incorporated into eval() statements. This pattern of code injection through date parameters demonstrates a fundamental flaw in the application's input sanitization mechanisms, where time-based data is not properly escaped or validated before being processed by dynamic code execution functions. The use of eval() in this context violates the principle of least privilege and creates a direct path for privilege escalation and system compromise.
The operational impact of this vulnerability extends far beyond simple code execution, as it provides attackers with complete control over the affected server environment. Remote code execution capabilities enable adversaries to perform actions such as data exfiltration, system reconnaissance, privilege escalation, and persistence establishment within the compromised infrastructure. The vulnerability affects the core reservation functionality of phpScheduleIt, potentially allowing attackers to manipulate scheduling data, access sensitive information, or disrupt service availability. Given that phpScheduleIt is commonly used in enterprise and organizational environments for managing critical resources, the compromise of such systems could result in significant business disruption and data breaches. The vulnerability's remote exploitability means that attackers do not require physical access or local credentials to leverage the flaw, making it particularly dangerous in publicly accessible environments.
Security practitioners should implement immediate mitigations including applying the official patch released for version 1.2.11, which addresses the input validation issues in both affected scripts. Additionally, organizations should consider implementing web application firewalls to monitor and block suspicious parameter patterns targeting these specific endpoints. Input validation should be strengthened through proper sanitization of all date parameters and elimination of eval() usage with user-supplied data. The vulnerability aligns with CWE-94, which specifically addresses "Improper Control of Generation of Code ('Code Injection')" and represents a classic example of how dynamic code execution functions can be exploited when combined with unsanitized user input. From an ATT&CK framework perspective, this vulnerability maps to techniques involving command and script injection, specifically T1059.007 for the execution of code through PHP eval functions, and T1078 for maintaining access through compromised applications. Organizations should also conduct comprehensive security assessments of their phpScheduleIt installations to identify any additional vulnerabilities that may exist in the broader application ecosystem.