CVE-2020-23355: 
PHP vulnerability analysis and mitigation

Codiad 2.8.4 contains a vulnerability in the authentication mechanism within /componetns/user/class.user.php:Authenticate() function that is susceptible to magic hash authentication bypass (NVD). The vulnerability was discovered and disclosed in January 2021.

The vulnerability stems from the use of loose comparison (==) in the authentication process when comparing password hashes. If the encrypted hash value for passwords forms certain formats of magic hashes (e.g., 0e123...), the authentication can be bypassed. This occurs because PHP's loose comparison treats strings beginning with '0e' followed by numbers as scientific notation, potentially leading to false positive matches (GitHub Issue).

The vulnerability allows an attacker to bypass authentication controls by exploiting the magic hash comparison weakness. A successful exploit could enable unauthorized access to the application with valid user credentials.

The vulnerability can be exploited by crafting specific password inputs that generate magic hash values matching the format of stored password hashes in the system. When these values are compared using loose comparison, they may be evaluated as equal even though they represent different passwords.

The vulnerability can be mitigated by implementing strict comparison (=) instead of loose comparison () when comparing password hashes. Additionally, upgrading to a patched version of Codiad that addresses this vulnerability is recommended.