Late-Unicode normalization vulnerability in SHIRASAGI

Vulnerability Description

SHIRASAGI is a Content Management System. Prior to version 1.18.0, SHIRASAGI is vulnerable to a Post-Unicode normalization issue. This happens when a logical validation or a security check is performed before a Unicode normalization. The Unicode character equivalent of a character would resurface after the normalization. The fix is initially performing the Unicode normalization and then strip for all whitespaces and then checking for a blank string. This issue has been fixed in version 1.18.0.

References

• https://github.com/shirasagi/shirasagi/security/advisories/GHSA-xr45-c2jv-2v9r
• https://github.com/shirasagi/shirasagi/blob/f249ce3f06f6bfbc0017b38f5c13de424334c3ea/app/models/concerns/rdf/object.rb#L68-L72
• https://sim4n6.beehiiv.com/p/unicode-characters-bypass-security-checks