CVE-2010-1097 in DeDeCMS
Summary
by MITRE
include/userlogin.class.php in DeDeCMS 5.5 GBK, when session.auto_start is enabled, allows remote attackers to bypass authentication and gain administrative access via a value of 1 for the _SESSION[dede_admin_id] parameter, as demonstrated by a request to uploads/include/dialog/select_soft_post.php.
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Analysis
by VulDB Data Team • 05/03/2026
The vulnerability identified as CVE-2010-1097 represents a critical authentication bypass flaw in DeDeCMS 5.5 GBK versions that exploits a fundamental weakness in session management and parameter handling. This issue specifically targets the include/userlogin.class.php component within the content management system, where the application fails to properly validate session parameters when the PHP session.auto_start directive is enabled. The vulnerability operates through a straightforward yet dangerous mechanism that allows remote attackers to manipulate session variables directly through HTTP requests.
The technical exploitation occurs when an attacker crafts a malicious request to uploads/include/dialog/select_soft_post.php and sets the _SESSION[dede_admin_id] parameter to a value of 1. This manipulation leverages the insecure session handling mechanism that occurs when session.auto_start is enabled, effectively allowing unauthorized users to assume administrative privileges without proper authentication. The vulnerability stems from a lack of proper input validation and session integrity checks within the application's authentication flow, creating an attack vector that directly manipulates the session state to bypass the normal login process.
From an operational perspective, this vulnerability presents a severe risk to DeDeCMS installations as it enables complete administrative control over affected systems. An attacker who successfully exploits this vulnerability can gain full access to the content management system, allowing them to modify website content, upload malicious files, create new user accounts, and potentially escalate privileges to gain access to underlying server resources. The remote nature of this attack means that no local system access is required, making it particularly dangerous for web applications that are publicly accessible. This type of vulnerability is classified under CWE-285 - Improper Authorization, which specifically addresses situations where the application fails to properly verify that the user has sufficient privileges to perform a requested operation.
The attack pattern aligns with techniques described in the MITRE ATT&CK framework under the privilege escalation and credential access domains, where attackers leverage application-level flaws to bypass authentication mechanisms. The vulnerability demonstrates poor input sanitization practices and highlights the dangers of enabling auto-start sessions in web applications without proper security controls. This issue is particularly concerning because it affects the core authentication system of the CMS, making it a high-value target for attackers seeking persistent access to web applications.
Mitigation strategies for CVE-2010-1097 should focus on multiple layers of defense including disabling session.auto_start in PHP configurations, implementing proper input validation and sanitization for all session parameters, and applying the latest security patches from DeDeCMS developers. Organizations should also consider implementing web application firewalls to detect and block suspicious session parameter manipulation attempts, along with regular security audits of session management components. The vulnerability underscores the importance of proper session handling practices and demonstrates why applications should never trust client-supplied session data without proper validation and authentication checks. Additionally, security monitoring should be enhanced to detect unusual patterns in session parameter usage that might indicate exploitation attempts.