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>

templates/repo/issue/view_content/comments.tmpl

@@ -615,7 +615,7 @@
 						{{else}}
 							{{$reviewerName = .Review.OriginalAuthor}}
 						{{end}}
-						{{ctx.Locale.Tr "repo.issues.review.dismissed" $reviewerName $createdStr | Safe}}
+						<span class="dismissed-message">{{ctx.Locale.Tr "repo.issues.review.dismissed" ($reviewerName | Escape) $createdStr | Safe}}</span>
 					</span>
 				</div>
 				{{if .Content}}

templates/repo/migrate/migrating.tmpl

@@ -21,12 +21,12 @@
 					<div class="ui stackable middle very relaxed page grid">
 						<div class="sixteen wide center aligned centered column">
 							<div id="repo_migrating_progress">
-								<p>{{ctx.Locale.Tr "repo.migrate.migrating" .CloneAddr | Safe}}</p>
+								<p>{{ctx.Locale.Tr "repo.migrate.migrating" (.CloneAddr | Escape) | Safe}}</p>
 								<p id="repo_migrating_progress_message"></p>
 							</div>
 							<div id="repo_migrating_failed" class="gt-hidden">
 								{{if .CloneAddr}}
-									<p>{{ctx.Locale.Tr "repo.migrate.migrating_failed" .CloneAddr | Safe}}</p>
+									<p>{{ctx.Locale.Tr "repo.migrate.migrating_failed" (.CloneAddr | Escape) | Safe}}</p>
 								{{else}}
 									<p>{{ctx.Locale.Tr "repo.migrate.migrating_failed_no_addr" | Safe}}</p>
 								{{end}}
@@ -58,7 +58,7 @@
 	<div class="content">
 		<div class="ui warning message">
 			{{ctx.Locale.Tr "repo.settings.delete_notices_1" | Safe}}<br>
-			{{ctx.Locale.Tr "repo.settings.delete_notices_2" .Repository.FullName | Safe}}
+			{{ctx.Locale.Tr "repo.settings.delete_notices_2" (.Repository.FullName | Escape) | Safe}}
 			{{if .Repository.NumForks}}<br>
 			{{ctx.Locale.Tr "repo.settings.delete_notices_fork_1"}}
 			{{end}}

templates/repo/settings/options.tmpl

@@ -906,7 +906,7 @@
 		<div class="content">
 			<div class="ui warning message">
 				{{ctx.Locale.Tr "repo.settings.delete_notices_1" | Safe}}<br>
-				{{ctx.Locale.Tr "repo.settings.delete_notices_2" .Repository.FullName | Safe}}
+				{{ctx.Locale.Tr "repo.settings.delete_notices_2" (.Repository.FullName | Escape) | Safe}}
 				{{if .Repository.NumForks}}<br>
 				{{ctx.Locale.Tr "repo.settings.delete_notices_fork_1"}}
 				{{end}}
@@ -941,7 +941,7 @@
 		<div class="content">
 			<div class="ui warning message">
 				{{ctx.Locale.Tr "repo.settings.delete_notices_1" | Safe}}<br>
-				{{ctx.Locale.Tr "repo.settings.wiki_delete_notices_1" .Repository.Name | Safe}}
+				{{ctx.Locale.Tr "repo.settings.wiki_delete_notices_1" (.Repository.Name | Escape) | Safe}}
 			</div>
 			<form class="ui form" action="{{.Link}}" method="post">
 				{{.CsrfTokenHtml}}

templates/repo/wiki/revision.tmpl

@@ -10,7 +10,7 @@
 					{{$title}}
 					<div class="ui sub header gt-word-break">
 						{{$timeSince := TimeSince .Author.When ctx.Locale}}
-						{{ctx.Locale.Tr "repo.wiki.last_commit_info" .Author.Name $timeSince | Safe}}
+						{{ctx.Locale.Tr "repo.wiki.last_commit_info" (.Author.Name | Escape) $timeSince | Safe}}
 					</div>
 				</div>
 			</div>

templates/repo/wiki/view.tmpl

@@ -40,7 +40,7 @@
 					{{$title}}
 					<div class="ui sub header">
 						{{$timeSince := TimeSince .Author.When ctx.Locale}}
-						{{ctx.Locale.Tr "repo.wiki.last_commit_info" .Author.Name $timeSince | Safe}}
+						{{ctx.Locale.Tr "repo.wiki.last_commit_info" (.Author.Name | Escape) $timeSince | Safe}}
 					</div>
 				</div>
 				<div class="eight wide right aligned column">

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()))
+		})
+	})
+}