From 6a7585f25977a7917119c7e4c0e6641740186c21 Mon Sep 17 00:00:00 2001
From: moodler <moodler>
Date: Fri, 14 Nov 2003 12:48:26 +0000
Subject: [PATCH] SECURITY FIX:  This patch prevents teachers from logging in
 as admins or                course creators!  I'll make an announcement to
 registered                administrators.

---
 course/loginas.php | 4 ++++
 user/lib.php       | 2 +-
 user/view.php      | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/course/loginas.php b/course/loginas.php
index 022de5f773..24aa7fd828 100644
--- a/course/loginas.php
+++ b/course/loginas.php
@@ -32,6 +32,10 @@
         error("This student is not in this course!");
     }
 
+    if (iscreator($user)) {
+        error("You can not login as this person!");
+    }
+
     // Login as this student and return to course home page.
 
     $teacher_name = "$USER->firstname $USER->lastname";
diff --git a/user/lib.php b/user/lib.php
index 2bbd422d41..2c376be0e6 100644
--- a/user/lib.php
+++ b/user/lib.php
@@ -203,7 +203,7 @@ function print_user($user, $course, $string, $countries) {
     if (isteacher($course->id)) {
         $timemidnight = usergetmidnight(time());
         echo "<a href=\"../course/user.php?id=$course->id&user=$user->id\">$string->activity</a><br>";
-        if (isstudent($course->id, $user->id)) {
+        if (isstudent($course->id, $user->id) and !iscreator($user->id)) {  // Includes admins
             echo "<a href=\"../course/unenrol.php?id=$course->id&user=$user->id\">$string->unenrol</a><br />";
             echo "<a href=\"../course/loginas.php?id=$course->id&user=$user->id\">$string->loginas</a><br />";
         }
diff --git a/user/view.php b/user/view.php
index 42cb332b03..732a2defe8 100644
--- a/user/view.php
+++ b/user/view.php
@@ -170,7 +170,7 @@
         echo "<input type=submit value=\"".get_string("activityreport")."\">";
         echo "</form></p></td>";
     }
-    if (isteacher($course->id) and ($USER->id != $user->id)) {
+    if (isteacher($course->id) and ($USER->id != $user->id) and !iscreator($user->id)) {
         echo "<td nowrap><p><form action=\"../course/loginas.php\" method=get>";
         echo "<input type=hidden name=id value=\"$course->id\">";
         echo "<input type=hidden name=user value=\"$user->id\">";
-- 
2.39.5