From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yann E. MORIN Date: Sun, 29 Mar 2020 18:49:16 +0200 Subject: [Buildroot] [PATCH 1/5] package/gvfs: fix CVE-2019-3827 In-Reply-To: <20200329160246.4053834-1-fontaine.fabrice@gmail.com> References: <20200329160246.4053834-1-fontaine.fabrice@gmail.com> Message-ID: <20200329164916.GH22325@scaer> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Fabrice, All, On 2020-03-29 18:02 +0200, Fabrice Fontaine spake thusly: > An incorrect permission check in the admin backend in gvfs before > version 1.39.4 was found that allows reading and modify arbitrary files > by privileged users without asking for password when no authentication > agent is running. This vulnerability can be exploited by malicious > programs running under privileges of users belonging to the wheel group > to further escalate its privileges by modifying system files without > user's knowledge. Successful exploitation requires uncommon system > configuration. > > Signed-off-by: Fabrice Fontaine Patch series applied to master, thanks. Any reason why you sent one patch for each CVE, rather than a single patch? Regards, Yann E. MORIN. > --- > ...authentication-agent-isn-t-available.patch | 46 +++++++++++++++++++ > package/gvfs/gvfs.mk | 3 ++ > 2 files changed, 49 insertions(+) > create mode 100644 package/gvfs/0001-admin-Prevent-access-if-any-authentication-agent-isn-t-available.patch > > diff --git a/package/gvfs/0001-admin-Prevent-access-if-any-authentication-agent-isn-t-available.patch b/package/gvfs/0001-admin-Prevent-access-if-any-authentication-agent-isn-t-available.patch > new file mode 100644 > index 0000000000..2715371534 > --- /dev/null > +++ b/package/gvfs/0001-admin-Prevent-access-if-any-authentication-agent-isn-t-available.patch > @@ -0,0 +1,46 @@ > +From d8d0c8c40049cfd824b2b90d0cd47914052b9811 Mon Sep 17 00:00:00 2001 > +From: Ondrej Holy > +Date: Wed, 2 Jan 2019 17:13:27 +0100 > +Subject: [PATCH] admin: Prevent access if any authentication agent isn't > + available > + > +The backend currently allows to access and modify files without prompting > +for password if any polkit authentication agent isn't available. This seems > +isn't usually problem, because polkit agents are integral parts of > +graphical environments / linux distributions. The agents can't be simply > +disabled without root permissions and are automatically respawned. However, > +this might be a problem in some non-standard cases. > + > +This affects only users which belong to wheel group (i.e. those who are > +already allowed to use sudo). It doesn't allow privilege escalation for > +users, who don't belong to that group. > + > +Let's return permission denied error also when the subject can't be > +authorized by any polkit agent to prevent this behavior. > + > +Closes: https://gitlab.gnome.org/GNOME/gvfs/issues/355 > + > +Signed-off-by: Fabrice Fontaine > +[Retrieved from: > +https://gitlab.gnome.org/GNOME/gvfs/commit/d8d0c8c40049cfd824b2b90d0cd47914052b9811] > +--- > + daemon/gvfsbackendadmin.c | 3 +-- > + 1 file changed, 1 insertion(+), 2 deletions(-) > + > +diff --git a/daemon/gvfsbackendadmin.c b/daemon/gvfsbackendadmin.c > +index ec0f2392..0f849008 100644 > +--- a/daemon/gvfsbackendadmin.c > ++++ b/daemon/gvfsbackendadmin.c > +@@ -130,8 +130,7 @@ check_permission (GVfsBackendAdmin *self, > + return FALSE; > + } > + > +- is_authorized = polkit_authorization_result_get_is_authorized (result) || > +- polkit_authorization_result_get_is_challenge (result); > ++ is_authorized = polkit_authorization_result_get_is_authorized (result); > + > + g_object_unref (result); > + > +-- > +2.24.1 > + > diff --git a/package/gvfs/gvfs.mk b/package/gvfs/gvfs.mk > index c380a710fb..6c927fa345 100644 > --- a/package/gvfs/gvfs.mk > +++ b/package/gvfs/gvfs.mk > @@ -15,6 +15,9 @@ GVFS_LICENSE = LGPL-2.0+ > GVFS_LICENSE_FILES = COPYING > GVFS_LIBS = $(TARGET_NLS_LIBS) > > +# 0001-admin-Prevent-access-if-any-authentication-agent-isn-t-available.patch > +GVFS_IGNORE_CVES += CVE-2019-3827 > + > # Export ac_cv_path_LIBGCRYPT_CONFIG unconditionally to prevent > # build system from searching the host paths. > GVFS_CONF_ENV = \ > -- > 2.25.1 > > _______________________________________________ > buildroot mailing list > buildroot at busybox.net > http://lists.busybox.net/mailman/listinfo/buildroot -- .-----------------.--------------------.------------------.--------------------. | Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: | | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ | | +33 561 099 427 `------------.-------: X AGAINST | \e/ There is no | | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. | '------------------------------^-------^------------------^--------------------'