CVE-2017-1000195 in October
Summary
by MITRE
October CMS build 412 is vulnerable to PHP object injection in asset move functionality resulting in ability to delete files limited by file permissions on the server.
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Analysis
by VulDB Data Team • 12/08/2019
The vulnerability identified as CVE-2017-1000195 affects October CMS version 412 and represents a critical security flaw in the asset management system that could enable unauthorized file deletion operations. This vulnerability specifically targets the file move functionality within the CMS asset handling mechanism, creating a pathway for malicious actors to exploit PHP object injection techniques. The flaw exists within the application's handling of user-supplied input during asset movement operations, where insufficient validation allows crafted payloads to be executed within the PHP environment. This type of vulnerability falls under the category of CWE-502, which specifically addresses PHP object injection flaws that occur when untrusted data is passed to the unserialize() function. The security implications extend beyond simple data manipulation as the vulnerability directly impacts the integrity and availability of the file system through the exploitation of the application's file handling capabilities.
The technical exploitation of this vulnerability occurs when an attacker manipulates the asset move functionality to inject malicious PHP objects into the system. The attack vector leverages the application's lack of proper input sanitization and validation during file operations, allowing an attacker to construct serialized PHP objects that, when processed by the unserialize() function, execute arbitrary code with the privileges of the web server. The vulnerability is particularly concerning because it operates within the legitimate file system permissions of the server, meaning that the attacker can only delete files that the web application itself has permission to access. This limitation, while reducing the potential scope of damage, still provides significant attack surface for unauthorized file deletion within the application's designated directories. The exploitation process typically involves crafting a specially formatted request that includes serialized PHP objects designed to trigger file deletion operations when the system attempts to process the asset move command.
The operational impact of this vulnerability extends beyond immediate file deletion capabilities to encompass broader security implications for the October CMS deployment. Organizations using affected versions face potential data loss, system compromise, and disruption of service availability. The vulnerability can be particularly damaging in environments where the web application has write access to critical system files or configuration data. Attackers can leverage this flaw to remove important application files, potentially leading to complete application failure or the ability to escalate privileges through the deletion of security-critical components. The attack requires minimal sophistication and can be automated, making it particularly dangerous for widespread deployment. From an operational standpoint, this vulnerability undermines the trust model of the application and creates potential for cascading failures when critical files are removed from the system. The impact is further amplified when considering that the vulnerability exists in a widely used content management system, meaning that exploitation could affect numerous installations across different organizations.
Mitigation strategies for CVE-2017-1000195 focus on immediate patching and configuration hardening measures to prevent exploitation of the PHP object injection vulnerability. The primary recommendation involves upgrading to a patched version of October CMS that addresses the specific serialization flaw in the asset handling functionality. Organizations should also implement strict input validation and sanitization measures for all user-supplied data, particularly within file operation contexts. The implementation of proper access controls and privilege separation ensures that the web application operates with minimal necessary permissions, reducing the potential impact of successful exploitation. Additionally, network-level controls such as web application firewalls can be deployed to monitor and block suspicious requests targeting the asset move functionality. Security monitoring should include detection of unusual file deletion patterns and unauthorized access attempts to the application's file system. The vulnerability aligns with ATT&CK technique T1059.007 for PHP injection and T1485 for data destruction, indicating that organizations should consider these attack patterns in their threat modeling and incident response planning. Regular security assessments and vulnerability scanning should be conducted to identify similar flaws in other components of the application stack, as this vulnerability demonstrates the importance of proper object serialization handling in web applications.