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authorCarlos O'Donell <carlos@redhat.com>2013-07-19 02:42:03 -0400
committerCarlos O'Donell <carlos@redhat.com>2013-07-21 15:39:55 -0400
commite4608715e6e1dd2adc91982fd151d5ba4f761d69 (patch)
tree04bc13d3736e14045f0f9fc37e0303a067f943cf /login
parentda2d62df77de66e5de5755228759f8bc18481871 (diff)
CVE-2013-2207, BZ #15755: Disable pt_chown.
The helper binary pt_chown tricked into granting access to another user's pseudo-terminal. Pre-conditions for the attack: * Attacker with local user account * Kernel with FUSE support * "user_allow_other" in /etc/fuse.conf * Victim with allocated slave in /dev/pts Using the setuid installed pt_chown and a weak check on whether a file descriptor is a tty, an attacker could fake a pty check using FUSE and trick pt_chown to grant ownership of a pty descriptor that the current user does not own. It cannot access /dev/pts/ptmx however. In most modern distributions pt_chown is not needed because devpts is enabled by default. The fix for this CVE is to disable building and using pt_chown by default. We still provide a configure option to enable hte use of pt_chown but distributions do so at their own risk.
Diffstat (limited to 'login')
-rw-r--r--login/Makefile8
1 files changed, 7 insertions, 1 deletions
diff --git a/login/Makefile b/login/Makefile
index 0bfe643136..430c6d93d6 100644
--- a/login/Makefile
+++ b/login/Makefile
@@ -30,9 +30,15 @@ routines := getlogin getlogin_r setlogin getlogin_r_chk \
CFLAGS-grantpt.c = -DLIBEXECDIR='"$(libexecdir)"'
-others = utmpdump pt_chown
+others = utmpdump
+
+include ../Makeconfig
+
+ifeq (yes,$(build-pt-chown))
+others += pt_chown
others-pie = pt_chown
install-others-programs = $(inst_libexecdir)/pt_chown
+endif
subdir-dirs = programs
vpath %.c programs