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[Fix] Decode Percent-encoded Characters in URL #17

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Merged
nsavinda merged 1 commit into from
Feb 4, 2025
Merged

[Fix] Decode Percent-encoded Characters in URL #17

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7 changes: 7 additions & 0 deletions servefiles/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@ import (
"html/template"
"log"
"net/http"
"net/url"
"os"
"path/filepath"

Expand Down Expand Up @@ -62,6 +63,12 @@ func httpRequestHandler(w http.ResponseWriter, req *http.Request) {
func fileHandler(w http.ResponseWriter, req *http.Request) {
// Strip the "/files" prefix from the request URL
path := "." + req.URL.Path[len("/files"):]
// Decode percent-encoded characters
path, err := url.PathUnescape(path)
if err != nil {
http.Error(w, "Invalid URL", http.StatusBadRequest)
return
}
Comment on lines +66 to +71
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@coderabbitai coderabbitai bot Feb 4, 2025

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⚠️ Potential issue

Add path sanitization to prevent directory traversal.

While the URL decoding is implemented correctly, the decoded path needs to be sanitized before use to prevent potential directory traversal attacks.

Apply this diff to add path sanitization:

 	// Decode percent-encoded characters
 	path, err := url.PathUnescape(path)
 	if err != nil {
-		http.Error(w, "Invalid URL", http.StatusBadRequest)
+		http.Error(w, "Invalid URL encoding", http.StatusBadRequest)
 		return
 	}
+	// Clean the path to prevent directory traversal
+	path = filepath.Clean(path)
+	if strings.HasPrefix(path, "..") {
+		http.Error(w, "Invalid path", http.StatusBadRequest)
+		return
+	}

Don't forget to add the required import:

+	"strings"
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
// Decode percent-encoded characters
path, err := url.PathUnescape(path)
if err != nil {
http.Error(w, "Invalid URL", http.StatusBadRequest)
return
}
// Decode percent-encoded characters
path, err := url.PathUnescape(path)
if err != nil {
http.Error(w, "Invalid URL encoding", http.StatusBadRequest)
return
}
// Clean the path to prevent directory traversal
path = filepath.Clean(path)
if strings.HasPrefix(path, "..") {
http.Error(w, "Invalid path", http.StatusBadRequest)
return
}


// Check if the path is a directory or a file
fileInfo, err := os.Stat(path)
Expand Down