Hi Mike, On Mon, Jun 24, 2019 at 08:28:11AM +0000, Mike Gabriel wrote: > On Di 18 Jun 2019 22:47:44 CEST, Sylvain Beucler wrote: > > > Package : glib2.0 > > Version : 2.42.1-1+deb8u1 > > CVE ID : CVE-2019-12450 > > Debian Bug : 929753 > > > > It was discovered that GLib does not properly restrict some file > > permissions while a copy operation is in progress; instead, default > > permissions are used. > > > > For Debian 8 "Jessie", this problem has been fixed in version > > 2.42.1-1+deb8u1. > > > > We recommend that you upgrade your glib2.0 packages. > > > > Further information about Debian LTS security advisories, how to apply > > these updates to your system and frequently asked questions can be > > found at: https://wiki.debian.org/LTS > > I wonder, if it would be good to have this upstream patch backported to > jessie's glib2.0, too, to have the file permission stuff complete: > > ``` > From 5e4da714f00f6bfb2ccd6d73d61329c6f3a08429 Mon Sep 17 00:00:00 2001 > From: Matthias Clasen <[email protected]> > Date: Tue, 22 Jan 2019 13:26:31 -0500 > Subject: [PATCH] keyfile settings: Use tighter permissions > > When creating directories, create them with 700 permissions, > instead of 777. > > Closes: #1658 > --- > gio/gkeyfilesettingsbackend.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > --- a/gio/gkeyfilesettingsbackend.c > +++ b/gio/gkeyfilesettingsbackend.c > @@ -89,7 +89,8 @@ > > contents = g_key_file_to_data (kfsb->keyfile, &length, NULL); > g_file_replace_contents (kfsb->file, contents, length, NULL, FALSE, > - G_FILE_CREATE_REPLACE_DESTINATION, > + G_FILE_CREATE_REPLACE_DESTINATION | > + G_FILE_CREATE_PRIVATE, > NULL, NULL, NULL); > > compute_checksum (kfsb->digest, contents, length); > @@ -640,7 +641,7 @@ > > kfsb->file = g_file_new_for_path (filename); > kfsb->dir = g_file_get_parent (kfsb->file); > - g_file_make_directory_with_parents (kfsb->dir, NULL, NULL); > + g_mkdir_with_parents (g_file_peek_path (kfsb->dir), 0700); > > kfsb->file_monitor = g_file_monitor (kfsb->file, 0, NULL, NULL); > kfsb->dir_monitor = g_file_monitor (kfsb->dir, 0, NULL, NULL); > > ``` > > The patch was not explicitly mentioned in the CVE, but I stumbled over it > when fixing glib2.0 for wheezy ELTS last month. (Unfortunately, the > g_mkdir_with_parents() symbol is not in jessie, for wheezy I skipped the > safe directory creation part).
This looks like another vulnerability, not related to copying files from a non-unix VFS, but to the creation of key/value files and their directory (mitigated by umask and the strict permissions of e.g. ~/.config). Do you know if this has a CVE? Maybe we can ask pkg-gnome-maintainers's point? (I didn't see this applied in other distros but I may have missed it.) Feel free to take over btw, I won't be much available until next week :) Cheers! Sylvain
