Coraza: Truncated multipart body bypasses MULTIPART_STRICT_ERROR (rule 200003) via silent io.ErrUnexpectedEOF handling

[ Description ]Official description

OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. From 3.4.0 until 3.8.0, the multipart processor in internal/bodyprocessors/multipart.go treats io.ErrUnexpectedEOF as nonfatal without setting MULTIPART_STRICT_ERROR. A remote attacker can submit a truncated multipart body that produces io.ErrUnexpectedEOF, causing parsing to stop without raising the strict-error signal used by the recommended defensive rule. Rules 200002 and 200003 do not fire, allowing multipart parser-disagreement payloads to reach a backend that interprets the truncated body differently. This issue is fixed in version 3.8.0.

[ Fixes ]Fixes and patches

• github.com/corazawaf/coraza/v3 3.8.0Fixed version · GitHub Advisories · go package github.com/corazawaf/coraza/v3: upgrade to 3.8.0 or later (affected >= 3.4.0, <= 3.7.0)

[ Packages ]Affected open-source packages

• github.com/corazawaf/coraza/v3 goAffected >= 3.4.0, <= 3.7.0 · fixed in 3.8.0 · GHSA-r3rm-qphw-hh76

[ References ]References

• github.com/corazawaf/coraza/commit/f94c81bec209f658120c418448d0590a549b71df
• github.com/corazawaf/coraza/releases/tag/v3.8.0
• github.com/corazawaf/coraza/security/advisories/GHSA-r3rm-qphw-hh76