fix(lib): add comprehensive XSS protection logic

Signed-off-by: Xe Iaso <me@xeiaso.net>
This commit is contained in:
Xe Iaso 2025-07-24 15:15:00 +00:00
parent 45ff8f526e
commit bad97c3929
No known key found for this signature in database
3 changed files with 65 additions and 51 deletions

View File

@ -264,7 +264,7 @@ func (s *Server) checkRules(w http.ResponseWriter, r *http.Request, cr policy.Ch
hash := rule.Hash()
lg.Debug("rule hash", "hash", hash)
s.respondWithStatus(w, r, fmt.Sprintf("%s %s", localizer.T("access_denied"), hash), s.policy.StatusCodes.Deny)
s.respondWithStatus(w, r, fmt.Sprintf("%s %s", localizer.T("access_denied"), hash), "/", s.policy.StatusCodes.Deny)
return true
case config.RuleChallenge:
lg.Debug("challenge requested")
@ -302,7 +302,7 @@ func (s *Server) handleDNSBL(w http.ResponseWriter, r *http.Request, ip string,
localizer.T("dronebl_entry"),
resp.String(),
localizer.T("see_dronebl_lookup"),
ip), s.policy.StatusCodes.Deny)
ip), "/", s.policy.StatusCodes.Deny)
return true
}
}
@ -388,13 +388,16 @@ func (s *Server) PassChallenge(w http.ResponseWriter, r *http.Request) {
redirURL, err := url.ParseRequestURI(redir)
if err != nil {
lg.Error("invalid redirect", "err", err)
s.respondWithError(w, r, localizer.T("invalid_redirect"))
s.respondWithStatus(w, r, localizer.T("invalid_redirect"), "/", http.StatusBadRequest)
return
}
if redirURL.Scheme != "" && redirURL.Scheme != "http" && redirURL.Scheme != "https" {
switch redirURL.Scheme {
case "", "http", "https":
// allowed
default:
lg.Error("XSS attempt blocked, invalid redirect scheme", "scheme", redirURL.Scheme)
s.respondWithStatus(w, r, localizer.T("invalid_redirect"), http.StatusBadRequest)
s.respondWithStatus(w, r, localizer.T("invalid_redirect"), "/", http.StatusBadRequest)
return
}
@ -463,7 +466,7 @@ func (s *Server) PassChallenge(w http.ResponseWriter, r *http.Request) {
case errors.As(err, &cerr):
switch {
case errors.Is(err, challenge.ErrFailed):
s.respondWithStatus(w, r, cerr.PublicReason, cerr.StatusCode)
s.respondWithStatus(w, r, cerr.PublicReason, "/", cerr.StatusCode)
case errors.Is(err, challenge.ErrInvalidFormat), errors.Is(err, challenge.ErrMissingField):
s.respondWithError(w, r, cerr.PublicReason)
}

View File

@ -1,6 +1,7 @@
package lib
import (
"bytes"
"encoding/json"
"fmt"
"io"
@ -834,49 +835,56 @@ func TestPassChallengeXSS(t *testing.T) {
},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
nonce := 0
elapsedTime := 420
calculated := ""
calcString := fmt.Sprintf("%s%d", chall.Challenge, nonce)
calculated = internal.SHA256sum(calcString)
t.Run("with test cookie", func(t *testing.T) {
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
nonce := 0
elapsedTime := 420
calculated := ""
calcString := fmt.Sprintf("%s%d", chall.Challenge, nonce)
calculated = internal.SHA256sum(calcString)
req, err := http.NewRequest(http.MethodGet, ts.URL+"/.within.website/x/cmd/anubis/api/pass-challenge", nil)
if err != nil {
t.Fatalf("can't make request: %v", err)
}
q := req.URL.Query()
q.Set("response", calculated)
q.Set("nonce", fmt.Sprint(nonce))
q.Set("redir", tc.redir)
q.Set("elapsedTime", fmt.Sprint(elapsedTime))
req.URL.RawQuery = q.Encode()
u, err := url.Parse(ts.URL)
if err != nil {
t.Fatal(err)
}
for _, ckie := range cli.Jar.Cookies(u) {
if ckie.Name == anubis.TestCookieName {
req.AddCookie(ckie)
req, err := http.NewRequest(http.MethodGet, ts.URL+"/.within.website/x/cmd/anubis/api/pass-challenge", nil)
if err != nil {
t.Fatalf("can't make request: %v", err)
}
}
resp, err := cli.Do(req)
if err != nil {
t.Fatalf("can't do request: %v", err)
}
q := req.URL.Query()
q.Set("response", calculated)
q.Set("nonce", fmt.Sprint(nonce))
q.Set("redir", tc.redir)
q.Set("elapsedTime", fmt.Sprint(elapsedTime))
req.URL.RawQuery = q.Encode()
body, _ := io.ReadAll(resp.Body)
u, err := url.Parse(ts.URL)
if err != nil {
t.Fatal(err)
}
if resp.StatusCode != http.StatusBadRequest {
t.Errorf("wanted status %d, got %d. body: %s", http.StatusBadRequest, resp.StatusCode, body)
}
})
}
for _, ckie := range cli.Jar.Cookies(u) {
if ckie.Name == anubis.TestCookieName {
req.AddCookie(ckie)
}
}
resp, err := cli.Do(req)
if err != nil {
t.Fatalf("can't do request: %v", err)
}
body, _ := io.ReadAll(resp.Body)
if bytes.Contains(body, []byte(tc.redir)) {
t.Log(string(body))
t.Error("found XSS in HTML body")
}
if resp.StatusCode != http.StatusBadRequest {
t.Errorf("wanted status %d, got %d. body: %s", http.StatusBadRequest, resp.StatusCode, body)
}
})
}
})
t.Run("no test cookie", func(t *testing.T) {
for _, tc := range testCases {
@ -899,8 +907,6 @@ func TestPassChallengeXSS(t *testing.T) {
q.Set("elapsedTime", fmt.Sprint(elapsedTime))
req.URL.RawQuery = q.Encode()
// Do NOT add the test cookie here
resp, err := cli.Do(req)
if err != nil {
t.Fatalf("can't do request: %v", err)
@ -908,6 +914,11 @@ func TestPassChallengeXSS(t *testing.T) {
body, _ := io.ReadAll(resp.Body)
if bytes.Contains(body, []byte(tc.redir)) {
t.Log(string(body))
t.Error("found XSS in HTML body")
}
if resp.StatusCode != http.StatusBadRequest {
t.Errorf("wanted status %d, got %d. body: %s", http.StatusBadRequest, resp.StatusCode, body)
}

View File

@ -192,13 +192,13 @@ func (s *Server) RenderBench(w http.ResponseWriter, r *http.Request) {
}
func (s *Server) respondWithError(w http.ResponseWriter, r *http.Request, message string) {
s.respondWithStatus(w, r, message, http.StatusInternalServerError)
s.respondWithStatus(w, r, message, "/", http.StatusInternalServerError)
}
func (s *Server) respondWithStatus(w http.ResponseWriter, r *http.Request, msg string, status int) {
func (s *Server) respondWithStatus(w http.ResponseWriter, r *http.Request, msg, redirect string, status int) {
localizer := localization.GetLocalizer(r)
templ.Handler(web.Base(localizer.T("oh_noes"), web.ErrorPage(msg, s.opts.WebmasterEmail, r.FormValue("redir"), localizer), s.policy.Impressum, localizer), templ.WithStatus(status)).ServeHTTP(w, r)
templ.Handler(web.Base(localizer.T("oh_noes"), web.ErrorPage(msg, s.opts.WebmasterEmail, redirect, localizer), s.policy.Impressum, localizer), templ.WithStatus(status)).ServeHTTP(w, r)
}
func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@ -238,12 +238,12 @@ func (s *Server) ServeHTTPNext(w http.ResponseWriter, r *http.Request) {
redir := r.FormValue("redir")
urlParsed, err := r.URL.Parse(redir)
if err != nil {
s.respondWithStatus(w, r, localizer.T("redirect_not_parseable"), http.StatusBadRequest)
s.respondWithStatus(w, r, localizer.T("redirect_not_parseable"), "/", http.StatusBadRequest)
return
}
if (len(urlParsed.Host) > 0 && len(s.opts.RedirectDomains) != 0 && !slices.Contains(s.opts.RedirectDomains, urlParsed.Host)) || urlParsed.Host != r.URL.Host {
s.respondWithStatus(w, r, localizer.T("redirect_domain_not_allowed"), http.StatusBadRequest)
s.respondWithStatus(w, r, localizer.T("redirect_domain_not_allowed"), "/", http.StatusBadRequest)
return
}