CVE-2008-6486 in SharedLog
Summary
by MITRE
PHP remote file inclusion vulnerability in slideshow_uploadvideo.content.php in SharedLog, when register_globals is enabled, allows remote attackers to execute arbitrary PHP code via a URL in the GLOBALS[root_dir] parameter.
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Analysis
by VulDB Data Team • 12/14/2017
The vulnerability identified as CVE-2008-6486 represents a critical remote file inclusion flaw within the SharedLog content management system, specifically affecting the slideshow_uploadvideo.content.php component. This vulnerability manifests when the PHP configuration parameter register_globals is enabled, creating a dangerous condition where user-supplied input can directly influence the global namespace of the application. The flaw occurs because the application fails to properly validate or sanitize the GLOBALS[root_dir] parameter, which is then used in a file inclusion operation without adequate input filtering. This configuration issue creates a pathway for attackers to inject malicious code through carefully crafted URLs passed as parameters, effectively bypassing normal security boundaries.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-88, which describes improper neutralization of special elements used in an OS command. In this case, the vulnerability enables attackers to inject arbitrary PHP code through the GLOBALS[root_dir] parameter, which is then processed by the application's file inclusion mechanism. The attack vector specifically leverages the dangerous combination of register_globals being enabled and the lack of proper input validation, creating a scenario where an attacker can manipulate the application's execution flow. When register_globals is enabled, all request parameters automatically become global variables, making it trivial for attackers to override critical application variables and inject malicious payloads that get executed as PHP code.
The operational impact of this vulnerability extends far beyond simple code execution, as it provides attackers with complete control over the affected server. Once successfully exploited, attackers can execute arbitrary commands on the server, potentially leading to full system compromise, data exfiltration, and persistence mechanisms. The vulnerability affects the core functionality of the SharedLog system, compromising the integrity and confidentiality of all data managed through the platform. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring physical access to the target system, making it particularly dangerous for web applications that are publicly accessible. This vulnerability also demonstrates the critical importance of proper input validation and the dangers of enabling deprecated PHP configuration options that introduce security risks.
Mitigation strategies for CVE-2008-6486 must address both the immediate vulnerability and underlying architectural issues. The primary recommendation involves disabling the register_globals PHP configuration option, which eliminates the core condition that enables this attack. Additionally, implementing proper input validation and sanitization techniques should be enforced throughout the application, ensuring that all user-supplied data is thoroughly checked before being used in any file inclusion operations. The application should employ a whitelist approach for file inclusion parameters, where only predetermined, trusted values are accepted. Security measures should include input validation using functions like filter_var or preg_match to ensure parameters contain only expected characters and patterns. Organizations should also implement proper access controls and monitoring to detect anomalous behavior that might indicate exploitation attempts. This vulnerability highlights the importance of following secure coding practices and adhering to the principle of least privilege, where applications should never trust user input and should always validate and sanitize data before processing. The ATT&CK framework categorizes this vulnerability under T1190 - Exploit Public-Facing Application, emphasizing the need for proper application hardening and regular security assessments to prevent such critical flaws from being exploited in production environments.