Highlights
Auth Bypass: 4 prior fixes. Scrutinize any change in this area.
Dbal/AclProvider.php: most-fixed (1 issue). Treat as high-risk during review.
2 high-severity fixes in this history; regressions here are high-impact.
Recurring patterns
The bug types that recur here, drawn from past fixes, not open vulnerabilities.
Auth Bypass: Using loose comparisons when constructing UserSecurityIdentity instances allowed invalid or edge-case usernames (like '0') to resolve to equivalent identities, resulting in authorization bypass. Strict equality checks are required during construction.
Auth Bypass: Weak type comparisons on domain object identifiers permitted distinct objects to be treated as equivalent. Enforcing string casting and strict non-empty checks on identifiers is necessary to prevent unauthorized access.
Auth Bypass: AclVoter failed to verify if requested security attributes were supported before voting on them, potentially causing votes to be cast or allowed inappropriately for unsupported attributes.