From 3b76b4889786c2d35996c5ed7a0de1f49f72d767 Mon Sep 17 00:00:00 2001 From: Raman Tenneti Date: Tue, 27 Nov 2018 10:51:09 -0800 Subject: AOSP/Email - Fixed - Security Vulnerability - Email App: Malicious app is able to compose message with hidden attachments and bypass attachments path checks attaching private files from /data/data/com.android.email/* + Ported the following CLs. Code is different from gmail. Made the changes to work with Email. ++ https://critique.corp.google.com/#review/136780360 +++ Add isExternal() to ComposeActivity.java and it always returns false. Treat body and quoted text as plaintext if intent is external. ++ https://critique.corp.google.com/#review/137654162 +++ Don't let other apps use our EXTRA_MESSAGE. Load EXTRA_MESSAGE only if action is LAUNCH_COMPOSE. LAUNCH_COMPOSE action is an internal only action: b/32068883. ++ https://critique.corp.google.com/#review/142296051 +++ Don't let external Intent use EXTRA_MESSAGE Bug: 32068883 Bug: 32502421 Bug: 32589229 Test: manual - Ran the following tests on Pixel phone. Tested the Email UI. $ adb install -r out/target/product/marlin/system/app/Email/Email.apk $ adb install -r app-debug.apk Success $ adb shell am start -n com.test.poc.poc32589229/.MainActivity -a android.intent.action.MAIN Starting: Intent { act=android.intent.action.MAIN cmp=com.test.poc.poc32589229/.MainActivity } Duplicated the steps in https://b.corp.google.com/issues/32589229#comment5 and didn't get the attachments after the fix (was getting attachments before the fix). logcat output: 11-21 03:45:48.927 11705 11705 I poc-test: sending a hidden file attachment 11-21 03:45:48.929 11705 11705 I poc-test: Sending contentType: text/html, previewImage: null 11-21 03:45:48.935 914 4482 I ActivityManager: START u0 {act=com.android.mail.intent.action.LAUNCH_COMPOSE pkg=com.android.email cmp=com.android.email/.activity.ComposeActivityEmail (has extras)} from uid 10072 11-21 03:45:48.935 914 4482 W ActivityManager: Permission Denial: starting Intent { act=com.android.mail.intent.action.LAUNCH_COMPOSE pkg=com.android.email cmp=com.android.email/.activity.ComposeActivityEmail (has extras) } from ProcessRecord{6941817 11705:com.test.poc.poc32589229/u0a72} (pid=11705, uid=10072) not exported from uid 10062 11-21 03:45:48.937 11705 11705 D AndroidRuntime: Shutting down VM --------- beginning of crash 11-21 03:45:48.940 11705 11705 E AndroidRuntime: FATAL EXCEPTION: main 11-21 03:45:48.940 11705 11705 E AndroidRuntime: Process: com.test.poc.poc32589229, PID: 11705 11-21 03:45:48.940 11705 11705 E AndroidRuntime: java.lang.IllegalStateException: Could not execute method for android:onClick ... 11-21 03:45:48.940 11705 11705 E AndroidRuntime: Caused by: java.lang.SecurityException: Permission Denial: starting Intent { act=com.android.mail.intent.action.LAUNCH_COMPOSE pkg=com.android.email cmp=com.android.email/.activity.ComposeActivityEmail (has extras) } from ProcessRecord{6941817 11705:com.test.poc.poc32589229/u0a72} (pid=11705, uid=10072) not exported from uid 10062 $ adb install -r out/target/product/marlin/testcases/EmailTests/EmailTests.apk Performing Streamed Install Success $ adb shell am instrument -w com.android.email.tests The number of failures are same as before (with or without this change). Tests run: 158, Failures: 5 Change-Id: If6e2a2efa08b75675c980b72735cde8252e95760 (cherry picked from commit 3526a4ac552f93a83ea838ddae5de45e1e068af0) --- src/com/android/mail/compose/ComposeActivity.java | 26 ++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/src/com/android/mail/compose/ComposeActivity.java b/src/com/android/mail/compose/ComposeActivity.java index b120c2e7b..b1bed47ee 100644 --- a/src/com/android/mail/compose/ComposeActivity.java +++ b/src/com/android/mail/compose/ComposeActivity.java @@ -466,6 +466,11 @@ public class ComposeActivity extends Activity implements OnClickListener, OnNavi launcher.startActivity(intent); } + /** Returns true if activity is started from an intent from an external application. */ + public boolean isExternal() { + return false; + } + @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); @@ -475,6 +480,16 @@ public class ComposeActivity extends Activity implements OnClickListener, OnNavi checkValidAccounts(); } + /** Used for escaping plaintext. If the input is null, then it will return an empty String. */ + private static String escapeAndReplaceHtml(CharSequence text) { + if (text == null) { + return ""; + } + String body = Html.escapeHtml(text); + // Replace \r\n and \n with
tags + return body.replaceAll("( | )", "
"); + } + private void finishCreate() { final Bundle savedState = mInnerSavedState; findViews(); @@ -503,6 +518,9 @@ public class ComposeActivity extends Activity implements OnClickListener, OnNavi message = (Message) intent.getParcelableExtra(ORIGINAL_DRAFT_MESSAGE); previews = intent.getParcelableArrayListExtra(EXTRA_ATTACHMENT_PREVIEWS); mRefMessage = (Message) intent.getParcelableExtra(EXTRA_IN_REFERENCE_TO_MESSAGE); + if (isExternal() && mRefMessage != null && !TextUtils.isEmpty(mRefMessage.bodyHtml)) { + mRefMessage.bodyHtml = escapeAndReplaceHtml(mRefMessage.bodyHtml); + } mRefMessageUri = (Uri) intent.getParcelableExtra(EXTRA_IN_REFERENCE_TO_MESSAGE_URI); if (Analytics.isLoggable()) { @@ -1310,6 +1328,9 @@ public class ComposeActivity extends Activity implements OnClickListener, OnNavi } String body = intent.getStringExtra(EXTRA_BODY); if (body != null) { + if (isExternal()) { + body = escapeAndReplaceHtml(body); + } setBody(body, false /* withSignature */); } } @@ -1455,7 +1476,10 @@ public class ComposeActivity extends Activity implements OnClickListener, OnNavi } else if (EXTRA_BODY.equals(extra)) { setBody(value, true /* with signature */); } else if (EXTRA_QUOTED_TEXT.equals(extra)) { - initQuotedText(value, true /* shouldQuoteText */); + if (isExternal()) { + value = escapeAndReplaceHtml(value); + } + initQuotedText(value, true /* shouldQuoteText */); } } } -- cgit v1.2.3