Coraza before 3.8.1 extracts multipart upload filenames with Go's mime.ParseMediaType, which silently ignores RFC 5987 filename parameters whose charset is not utf-8 or us-ascii. Unauthenticated attackers can send a decoy filename with filename=iso-8859-1''shell.php, or filename alone, so FILES-based rules never see the real name, letting dangerous uploads reach backends that honor filename.

Coraza from 3.0.4 before 3.8.1 contains a request body inspection bypass because request-body processor selection compares the entire Content-Type value exactly, so URL-encoded bodies whose Content-Type carries a media-type parameter are never parsed. Unauthenticated attackers can send application/x-www-form-urlencoded; charset=UTF-8 to keep ARGSPOST and REQUESTBODY empty, evading body rules while the backend still processes the payload.

Coraza from 3.0.0 before 3.8.1 has a JSON body processor that flattens nested properties into dot-separated ARGSPOST names without escaping literal dots, so distinct properties collide. Unauthenticated attackers can add a later dotted property such as account.role that overwrites a malicious nested value, hiding SQL injection payloads from OWASP CRS rules while backends still receive them.

Summary

Due to the misuse of log.Fatalf, the application using coraza crashed after receiving crafted requests from attackers.

Details

https://github.com/corazawaf/coraza/blob/82157f85f24c6107667bf0f686b71a72aafdf8a5/internal/bodyprocessors/multipart.go#L26-L29 The bodyprocessors of multipart uses log.Fatalf to handle errors from the mime.ParseMediaType, but log.Fatalf calls os.Exit directly after logging the error. https://github.com/golang/go/blob/a031f4ef83edc132d5f49382bfef491161de2476/src/log/log.go#L288-L291 This means that the application will immediately crash after receiving a malicious request that triggers an error in mime.ParseMediaType.

PoC

The server can be demonstrated by https://github.com/corazawaf/coraza/tree/main/examples/http-server

After sending this request POST / HTTP/1.1 Host: 127.0.0.1:8090 User-Agent: curl/8.1.2 Accept: / Content-Length: 199 Content-Type: multipart/form-data; boundary=------------------------5fa6351b877326a1; a=1; a=2 Connection: close

--------------------------5fa6351b877326a1 Content-Disposition: form-data; name="file"; filename="123" Content-Type: application/octet-stream

123

--------------------------5fa6351b877326a1--

The server will crash immediately. The a=1; a=2 in Content-Type makes mime: duplicate parameter name error.

Impact

I believe the vulnerability was introduced by the following commit: https://github.com/corazawaf/coraza/commit/24af0c8cf4f10bab558740b595712be3b85493ec.

Mitigation

The error from mime.ParseMediaType should return directly.