CVE-2018-16239 in DamiCMS
Summary
by MITRE
An issue was discovered in damiCMS V6.0.1. It relies on the PHP time() function for cookies, which makes it possible to determine the cookie for an existing admin session via 10800 guesses.
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Analysis
by VulDB Data Team • 03/19/2020
The vulnerability identified as CVE-2018-16239 affects damiCMS version 6.0.1, presenting a significant security weakness in the application's session management mechanism. This flaw stems from the application's reliance on PHP's time() function for generating cookie values, creating a predictable session identifier that can be exploited by attackers. The vulnerability represents a critical weakness in the cryptographic implementation of session tokens, as it fundamentally undermines the randomness and unpredictability required for secure session management. The issue allows attackers to perform brute force attacks against admin sessions by making only 10800 guesses, demonstrating a severe lack of entropy in the cookie generation process.
The technical implementation of this vulnerability exploits the deterministic nature of PHP's time() function, which returns the current Unix timestamp as an integer value. When this timestamp is used directly or with minimal modification to create session cookies, it creates a narrow window of opportunity for attackers to guess valid session tokens. This approach reduces the complexity of session hijacking from the typical exponential difficulty of random token guessing to a linear search through a limited timestamp range. The vulnerability specifically affects the session management component of damiCMS, where the time-based approach to cookie generation creates a predictable pattern that can be systematically enumerated. This flaw aligns with CWE-330, which addresses the use of insufficiently random values in security-critical contexts, and represents a classic example of weak randomness in cryptographic operations.
The operational impact of this vulnerability extends beyond simple session hijacking, as it provides attackers with a direct path to administrative access within the content management system. With only 10800 guesses required to compromise an existing admin session, an attacker can effectively bypass authentication mechanisms entirely, gaining full administrative privileges. This creates a severe risk for organizations relying on damiCMS, as it allows for complete system compromise without requiring additional exploitation techniques. The vulnerability also represents a significant threat to data integrity and confidentiality, as administrators can access sensitive content, modify system configurations, and potentially exfiltrate data. The low computational overhead required for exploitation makes this vulnerability particularly dangerous in automated attack scenarios, where bots can quickly iterate through the possible timestamp values to obtain valid sessions.
Mitigation strategies for this vulnerability must address the fundamental flaw in the session token generation mechanism. Organizations should immediately upgrade to a patched version of damiCMS that implements proper cryptographic random number generation for session identifiers, ensuring that session tokens are generated using cryptographically secure random functions such as openssl_random_pseudo_bytes() or random_bytes(). The implementation should incorporate sufficient entropy to prevent brute force attacks, typically requiring at least 128 bits of randomness for secure session management. Additionally, administrators should implement session timeout mechanisms, enforce secure cookie attributes including HttpOnly and Secure flags, and consider implementing additional authentication layers such as two-factor authentication to provide defense in depth. This vulnerability demonstrates the critical importance of proper cryptographic implementation in web applications and aligns with ATT&CK technique T1566, which covers credential harvesting through various means including session hijacking and brute force attacks. Organizations should also conduct regular security assessments to identify similar weaknesses in session management across their web applications, ensuring that all session tokens are generated using cryptographically secure methods that prevent predictable patterns from emerging in the authentication process.