Fix XSS vulnerabilities (#29336)

- The Wiki page did not sanitize author name
- the reviewer name on a "dismiss review" comment is also affected
- the migration page has some spots

---------

Signed-off-by: jolheiser <john.olheiser@gmail.com>
Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-authored-by: jolheiser <john.olheiser@gmail.com>

tests/integration/xss_test.go

@@ -4,13 +4,23 @@
 package integration
 
 import (
+	"context"
+	"fmt"
 	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
 	"testing"
+	"time"
 
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/tests"
 
+	gogit "github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/plumbing/object"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -37,3 +47,78 @@ func TestXSSUserFullName(t *testing.T) {
 		htmlDoc.doc.Find("div.content").Find(".header.text.center").Text(),
 	)
 }
+
+func TestXSSWikiLastCommitInfo(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		// Prepare the environment.
+		dstPath := t.TempDir()
+		r := fmt.Sprintf("%suser2/repo1.wiki.git", u.String())
+		u, err := url.Parse(r)
+		assert.NoError(t, err)
+		u.User = url.UserPassword("user2", userPassword)
+		assert.NoError(t, git.CloneWithArgs(context.Background(), git.AllowLFSFiltersArgs(), u.String(), dstPath, git.CloneRepoOptions{}))
+
+		// Use go-git here, because using git wouldn't work, it has code to remove
+		// `<`, `>` and `\n` in user names. Even though this is permitted and
+		// wouldn't result in a error by a Git server.
+		gitRepo, err := gogit.PlainOpen(dstPath)
+		if err != nil {
+			panic(err)
+		}
+
+		w, err := gitRepo.Worktree()
+		if err != nil {
+			panic(err)
+		}
+
+		filename := filepath.Join(dstPath, "Home.md")
+		err = os.WriteFile(filename, []byte("Oh, a XSS attack?"), 0o644)
+		if !assert.NoError(t, err) {
+			t.FailNow()
+		}
+
+		_, err = w.Add("Home.md")
+		if !assert.NoError(t, err) {
+			t.FailNow()
+		}
+
+		_, err = w.Commit("Yay XSS", &gogit.CommitOptions{
+			Author: &object.Signature{
+				Name:  `Gusted <script class="evil">alert('Oh no!');</script>`,
+				Email: "valid@example.org",
+				When:  time.Date(2024, time.January, 31, 0, 0, 0, 0, time.UTC),
+			},
+		})
+		if !assert.NoError(t, err) {
+			t.FailNow()
+		}
+
+		// Push.
+		_, _, err = git.NewCommand(git.DefaultContext, "push").AddArguments(git.ToTrustedCmdArgs([]string{"origin", "master"})...).RunStdString(&git.RunOpts{Dir: dstPath})
+		assert.NoError(t, err)
+
+		// Check on page view.
+		t.Run("Page view", func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			req := NewRequest(t, http.MethodGet, "/user2/repo1/wiki/Home")
+			resp := MakeRequest(t, req, http.StatusOK)
+			htmlDoc := NewHTMLParser(t, resp.Body)
+
+			htmlDoc.AssertElement(t, "script.evil", false)
+			assert.EqualValues(t, `Gusted edited this page 0001-01-01 00:00:00 +00:00`, strings.TrimSpace(htmlDoc.Find(".ui.sub.header").Text()))
+		})
+
+		// Check on revisions page.
+		t.Run("Revision page", func(t *testing.T) {
+			defer tests.PrintCurrentTest(t)()
+
+			req := NewRequest(t, http.MethodGet, "/user2/repo1/wiki/Home?action=_revision")
+			resp := MakeRequest(t, req, http.StatusOK)
+			htmlDoc := NewHTMLParser(t, resp.Body)
+
+			htmlDoc.AssertElement(t, "script.evil", false)
+			assert.EqualValues(t, `Gusted edited this page 0001-01-01 00:00:00 +00:00`, strings.TrimSpace(htmlDoc.Find(".ui.sub.header").Text()))
+		})
+	})
+}