Description
YesWiki is a wiki system written in PHP. Prior to version 4.6.6, an unsafe execution vulnerability exists in the Bazar form field calculator (CalcField.php) of YesWiki. The application attempts to sanitize user-defined mathematical formulas using a complex recursive regular expression before passing them to the PHP eval() function. This implementation is inherently flawed: it is vulnerable to Regular Expression Denial of Service (ReDoS / Stack Overflow) which can crash the server, and it creates a high-risk architecture where any logic bypass directly results in arbitrary PHP code execution. Version 4.6.6 patches the issue.
Problem types
CWE-94: Improper Control of Generation of Code ('Code Injection')
CWE-1333: Inefficient Regular Expression Complexity
Product status
References
github.com/...eswiki/security/advisories/GHSA-px5m-h76g-p7p8
github.com/...ommit/dd2bd8fb099de0d21504bda8a810693b3fcb8e52
github.com/YesWiki/yeswiki/releases/tag/v4.6.6