Hi, On Mi 26 Jun 2019 14:55:46 CEST, Sylvain Beucler wrote:
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 <firstname.lastname@example.org> 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 :)
I just requested a CVE for this from Mitre. Request ist now waiting for review on their side...
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