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author | Carlos O'Donell <carlos@redhat.com> | 2013-07-19 02:42:03 -0400 |
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committer | Carlos O'Donell <carlos@redhat.com> | 2013-07-21 15:39:55 -0400 |
commit | e4608715e6e1dd2adc91982fd151d5ba4f761d69 (patch) | |
tree | 04bc13d3736e14045f0f9fc37e0303a067f943cf /sysdeps/unix/sysv/linux/grantpt.c | |
parent | da2d62df77de66e5de5755228759f8bc18481871 (diff) | |
download | glibc-e4608715e6e1dd2adc91982fd151d5ba4f761d69.tar.gz glibc-e4608715e6e1dd2adc91982fd151d5ba4f761d69.tar.xz glibc-e4608715e6e1dd2adc91982fd151d5ba4f761d69.zip |
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 'sysdeps/unix/sysv/linux/grantpt.c')
-rw-r--r-- | sysdeps/unix/sysv/linux/grantpt.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sysdeps/unix/sysv/linux/grantpt.c b/sysdeps/unix/sysv/linux/grantpt.c index 0a3cd472fa..8cebde36ed 100644 --- a/sysdeps/unix/sysv/linux/grantpt.c +++ b/sysdeps/unix/sysv/linux/grantpt.c @@ -11,7 +11,7 @@ #include "pty-private.h" - +#if HAVE_PT_CHOWN /* Close all file descriptors except the one specified. */ static void close_all_fds (void) @@ -38,6 +38,7 @@ close_all_fds (void) __dup2 (STDOUT_FILENO, STDERR_FILENO); } } -#define CLOSE_ALL_FDS() close_all_fds() +# define CLOSE_ALL_FDS() close_all_fds() +#endif #include <sysdeps/unix/grantpt.c> |