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| author | Carlos O'Donell <carlos@redhat.com> | 2013-07-19 02:42:03 -0400 |
|---|---|---|
| committer | Carlos O'Donell <carlos@redhat.com> | 2013-07-21 15:39:55 -0400 |
| commit | e4608715e6e1dd2adc91982fd151d5ba4f761d69 (patch) | |
| tree | 04bc13d3736e14045f0f9fc37e0303a067f943cf /login | |
| parent | da2d62df77de66e5de5755228759f8bc18481871 (diff) | |
| download | glibc-e4608715e6e1dd2adc91982fd151d5ba4f761d69.tar.gz | |
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/Makefile | 8 |
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 |