Coraza has potential denial of service vulnerability
Date: 2023-06
Affected: go/github.com/corazawaf/coraza/v2, go/github.com/corazawaf/coraza/v3
Attack vector: dos
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2023-40586
CWE: CWE-400
CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

### 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/24af0c8cf4f10bab558740b595712be3b8


Mitigations:

Architectural layers (MAESTRO):