Initial commit

1 files changed, 60 insertions, 0 deletions

diff --git a/CVE-2017-17450-netfilter-xt_osf-Add-missing-permission-checks.patch b/CVE-2017-17450-netfilter-xt_osf-Add-missing-permission-checks.patch
new file mode 100644
index 0000000..992c336
--- /dev/null
+++ b/CVE-2017-17450-netfilter-xt_osf-Add-missing-permission-checks.patch
@@ -0,0 +1,60 @@
+From 916a27901de01446bcf57ecca4783f6cff493309 Mon Sep 17 00:00:00 2001
+From: Kevin Cernekee <cernekee@chromium.org>
+Date: Tue, 5 Dec 2017 15:42:41 -0800
+Subject: [PATCH] netfilter: xt_osf: Add missing permission checks
+
+The capability check in nfnetlink_rcv() verifies that the caller
+has CAP_NET_ADMIN in the namespace that "owns" the netlink socket.
+However, xt_osf_fingers is shared by all net namespaces on the
+system.  An unprivileged user can create user and net namespaces
+in which he holds CAP_NET_ADMIN to bypass the netlink_net_capable()
+check:
+
+    vpnns -- nfnl_osf -f /tmp/pf.os
+
+    vpnns -- nfnl_osf -f /tmp/pf.os -d
+
+These non-root operations successfully modify the systemwide OS
+fingerprint list.  Add new capable() checks so that they can't.
+
+Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
+Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
+---
+ net/netfilter/xt_osf.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/net/netfilter/xt_osf.c b/net/netfilter/xt_osf.c
+index 36e14b1f061d..a34f314a8c23 100644
+--- a/net/netfilter/xt_osf.c
++++ b/net/netfilter/xt_osf.c
+@@ -19,6 +19,7 @@
+ #include <linux/module.h>
+ #include <linux/kernel.h>
+ 
++#include <linux/capability.h>
+ #include <linux/if.h>
+ #include <linux/inetdevice.h>
+ #include <linux/ip.h>
+@@ -70,6 +71,9 @@ static int xt_osf_add_callback(struct net *net, struct sock *ctnl,
+ 	struct xt_osf_finger *kf = NULL, *sf;
+ 	int err = 0;
+ 
++	if (!capable(CAP_NET_ADMIN))
++		return -EPERM;
++
+ 	if (!osf_attrs[OSF_ATTR_FINGER])
+ 		return -EINVAL;
+ 
+@@ -115,6 +119,9 @@ static int xt_osf_remove_callback(struct net *net, struct sock *ctnl,
+ 	struct xt_osf_finger *sf;
+ 	int err = -ENOENT;
+ 
++	if (!capable(CAP_NET_ADMIN))
++		return -EPERM;
++
+ 	if (!osf_attrs[OSF_ATTR_FINGER])
+ 		return -EINVAL;
+ 
+-- 
+2.15.1
+