CVE-2018-9175 in DeDeCMS
Summary
by MITRE
DedeCMS 5.7 allows remote attackers to execute arbitrary PHP code via the egroup parameter to uploads/dede/stepselect_main.php because code within the database is accessible to uploads/dede/sys_cache_up.php.
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Analysis
by VulDB Data Team • 01/20/2020
The vulnerability identified as CVE-2018-9175 affects DedeCMS version 5.7, representing a critical remote code execution flaw that enables attackers to execute arbitrary PHP code on affected systems. This vulnerability stems from improper input validation and insufficient access controls within the content management system's upload and cache handling mechanisms. The flaw specifically manifests through the egroup parameter in the uploads/dede/stepselect_main.php file, which creates a dangerous pathway for malicious code injection.
The technical root cause of this vulnerability lies in the insecure handling of database code execution within the system's cache update functionality. When the system processes the egroup parameter, it fails to properly sanitize or validate the input before incorporating it into the database operations. This oversight allows attackers to inject malicious PHP code that gets stored in the database and subsequently executed when the system accesses the uploads/dede/sys_cache_up.php file. The vulnerability demonstrates a classic case of insecure deserialization and code injection, where user-controllable data is directly used in system operations without proper sanitization.
The operational impact of CVE-2018-9175 is severe and far-reaching for organizations using affected DedeCMS installations. Attackers can leverage this vulnerability to gain complete control over the web server hosting the CMS, potentially leading to data breaches, system compromise, and unauthorized access to sensitive information. The remote nature of the exploit means that attackers do not require physical access to the system or prior authentication credentials to exploit the vulnerability. This makes the attack surface particularly wide and the risk of exploitation high, as the vulnerability can be triggered from any location with internet access. The ability to execute arbitrary PHP code opens doors for attackers to perform various malicious activities including data exfiltration, privilege escalation, and establishing persistent backdoors.
This vulnerability aligns with CWE-94, which describes the weakness of "Improper Control of Generation of Code ('Code Injection')" and reflects patterns commonly found in the ATT&CK framework under the technique of "Command and Scripting Interpreter" with specific implications for web application exploitation. Organizations should immediately implement mitigation strategies including updating to patched versions of DedeCMS, implementing proper input validation and sanitization procedures, restricting file upload capabilities, and monitoring for suspicious database access patterns. Additionally, network segmentation and web application firewalls should be deployed to limit the potential impact of such vulnerabilities. The incident underscores the critical importance of secure coding practices and regular security assessments in content management systems to prevent similar vulnerabilities from compromising system integrity and user data security.