Subject: [ASA-201801-9] glibc: multiple issues

Arch Linux Security Advisory ASA-201801-9
=========================================

Severity: High
Date    : 2018-01-10
CVE-ID  : CVE-2017-15670 CVE-2017-15671
Package : glibc
Type    : multiple issues
Remote  : Yes
Link    : https://security.archlinux.org/AVG-460

Summary
=======

The package glibc before version 2.26-9 is vulnerable to multiple
issues including arbitrary code execution and denial of service.

Resolution
==========

Upgrade to 2.26-9.

# pacman -Syu "glibc>=2.26-9"

The problems have been fixed upstream but no release is available yet.

Workaround
==========

None.

Description
===========

- CVE-2017-15670 (arbitrary code execution)

The GNU C Library (aka glibc or libc6) before 2.27 contains an off-by-
one error leading to a heap-based buffer overflow in the glob function
in glob.c, related to the processing of home directories using the ~
operator followed by a long string.

- CVE-2017-15671 (denial of service)

The glob function in glob.c in the GNU C Library (aka glibc or libc6)
before 2.27, when invoked with GLOB_TILDE, could skip freeing allocated
memory when processing the ~ operator with a long user name,
potentially leading to a denial of service (memory leak).

Impact
======

A remote attacker is able to execute arbitrary code on the host or
crash a target application that is using glibc functions for globbing
by providing a crafted input to it.

References
==========

http://seclists.org/oss-sec/2017/q4/119
https://sourceware.org/bugzilla/show_bug.cgi?id=22320
https://bugzilla.redhat.com/show_bug.cgi?id=1504804
https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=a76376df7c07e577a9515c3faa5dbd50bda5da07
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=2d1bd71ec70a31b01d01b734faa66bb1ed28961f
https://sourceware.org/bugzilla/show_bug.cgi?id=22325
https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=f1cf98b583787cfb6278baea46e286a0ee7567fd
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=6803dda53781f7da920f568a31610d41e5c3a351
https://security.archlinux.org/CVE-2017-15670
https://security.archlinux.org/CVE-2017-15671