Fix security problem in lilypond-invoke-editor (issue 336240043 by address@hidden)

[knupero]

Reviewers: ,

Message:
This security problem was introduced in 2005.

Description:
Fix security problem in lilypond-invoke-editor

If lilypond-invoke-editor was installed as a
general uri-helper it was easy to abuse it to
execute arbitrary code on an attacked system.

With this patch lilypond-invoke-editor only
handles textedit URIs.

We could have fixed URI passing to the browser,
but it is not our job to provide a general
URI helper. Other software (e.g. xdg-open and
friends) should be used for that.

Signed-off-by: Knut Petersen <address@hidden>

Please review this at https://codereview.appspot.com/336240043/

Affected files (+11, -20 lines):
  M Documentation/de/usage/external.itely
  M Documentation/usage/external.itely
  M scripts/lilypond-invoke-editor.scm


Index: Documentation/de/usage/external.itely
diff --git a/Documentation/de/usage/external.itely  
b/Documentation/de/usage/external.itely
index  
6f57989516fd4d001a36e3a98c7c2ab42992a981..5a8fe66bd6974ee1a99a8c83c85af4f1ccf3b20f  
100644
--- a/Documentation/de/usage/external.itely
+++ b/Documentation/de/usage/external.itely
@@ -49,8 +49,9 @@ zu finden, indem man auf sie im PDF-Programm klickt.  Das  
erleichtert
 es, die Stellen zu finden, die Fehler in der Notation verursachen.

 Wenn diese Funktionalität aktiv ist, fügt LilyPond Hyperlinks zur
-PDF-Datei hinzu.  Diese Hyperlinks werden an den Webbrowser gesendet,
-der einen Texteditor mit dem Cursor an der richtigen Stelle öffnet.
+PDF-Datei hinzu.  Diese Hyperlinks können an ein @q{URI-Hilfsprogramm}
+gesendet werden, das dann einen Texteditor mit dem Cursor an der
+richtigen Stelle öffnet.

 Damit diese Kettenreaktion funktionieren kann, müssen Sie das
 PDF-Programm dazu anweisen, Hyperlinks zu folgen, indem das Skript
@@ -65,10 +66,9 @@ entweder in @file{/etc/xpdfrc} oder als  
@file{$HOME/.xpdfrc}:
 urlCommand     "lilypond-invoke-editor %s"
 @end example

-Das Programm @file{lilypond-invoke-editor} ist ein kleines
-Hilfsprogramm.  Es ruft einen Editor für besondere @code{textedit}-URIs#
-auf und einen Webbrowser für andere.  Es testes die Umgebungsvariable
address@hidden nach folgenden Mustern:
+Das Programm @file{lilypond-invoke-editor} ist das @q{URI-Hilfsprogramm}.
+Es ruft einen Editor für @code{textedit}-URIs# auf.  Es testet die
+Umgebungsvariable @code{EDITOR} nach folgenden Mustern:

 @table @code
 @item emacs
Index: Documentation/usage/external.itely
diff --git a/Documentation/usage/external.itely  
b/Documentation/usage/external.itely
index  
659abd27ba934d002216b614cc92573bddb07db9..00a693c4c2faa022b0b94198ec8bf9fa6d6afcb0  
100644
--- a/Documentation/usage/external.itely
+++ b/Documentation/usage/external.itely
@@ -44,9 +44,8 @@ error in the sheet music.
 @subsection Configuring the system

 When this functionality is active, LilyPond adds hyperlinks to PDF and
-SVG files.  These hyperlinks are sent to a @q{URI helper} or a
-web-browser, which opens a text-editor with the cursor in the right
-place.
+SVG files.  These hyperlinks are sent to a @q{URI helper}, which opens
+a text-editor with the cursor in the right place.

 To make this chain work, you should configure your PDF viewer to
 follow hyperlinks using the @file{lilypond-invoke-editor} script
@@ -54,8 +53,8 @@ supplied with LilyPond.

 The program @file{lilypond-invoke-editor} is a small helper
 program.  It will invoke an editor for the special @code{textedit}
-URIs, and run a web browser for others.  It tests the environment
-variable @code{EDITOR} for the following patterns,
+URIs.  It tests the environment variable @code{EDITOR} for the following
+patterns,

 @table @code
 @item emacs
Index: scripts/lilypond-invoke-editor.scm
diff --git a/scripts/lilypond-invoke-editor.scm  
b/scripts/lilypond-invoke-editor.scm
index  
6658f50166dfe4d98f56d2d2aad068d4e291f864..3e485f53ec67abd1e0d18079314164f68e6c6e57  
100644
--- a/scripts/lilypond-invoke-editor.scm
+++ b/scripts/lilypond-invoke-editor.scm
@@ -126,13 +126,6 @@ Options:
                  (_ "failed to invoke editor: ~a") command)
          (exit 1)))))

-(define (run-browser uri)
-  (system
-   (if (getenv "BROWSER")
-       (format #f "~a ~a" (getenv "BROWSER") uri)
-       (format #f "firefox -remote 'OpenURL(~a,new-tab)'" uri))))
-
-
 (define (strip-framework-path var)
   (define pat "lilypond/usr")
   (if (getenv var)
@@ -169,7 +162,6 @@ Options:
     (strip-framework-path "LD_LIBRARY_PATH")
     (let* ((uri (car files)))
       (if (is-textedit-uri? uri)
-         (run-editor uri)
-         (run-browser uri)))))
+         (run-editor uri)))))

 (main (command-line))