From e4608715e6e1dd2adc91982fd151d5ba4f761d69 Mon Sep 17 00:00:00 2001 From: Carlos O'Donell Date: Fri, 19 Jul 2013 02:42:03 -0400 Subject: 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. --- config.h.in | 3 +++ 1 file changed, 3 insertions(+) (limited to 'config.h.in') diff --git a/config.h.in b/config.h.in index 6284e2a99b..a85f131255 100644 --- a/config.h.in +++ b/config.h.in @@ -238,4 +238,7 @@ /* The ARM hard-float ABI is being used. */ #undef HAVE_ARM_PCS_VFP +/* The pt_chown binary is being built and used by grantpt. */ +#undef HAVE_PT_CHOWN + #endif -- cgit v1.2.3