Topic

An update for glibc is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The glibc packages provide the standard C libraries (libc), POSIX thread libraries (libpthread), standard math libraries (libm), and the name service cache daemon (nscd) used by multiple programs on the system. Without these libraries, the Linux system cannot function correctly.

Security Fix(es):

• glibc: realpath() buffer underflow when getcwd() returns relative path allows privilege escalation (CVE-2018-1000001)
• glibc: Buffer overflow in glob with GLOB_TILDE (CVE-2017-15670)
• glibc: Buffer overflow during unescaping of user names with the ~ operator (CVE-2017-15804)
• glibc: denial of service in getnetbyname function (CVE-2014-9402)
• glibc: DNS resolver NULL pointer dereference with crafted record type (CVE-2015-5180)
• glibc: Fragmentation attacks possible when EDNS0 is enabled (CVE-2017-12132)

For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section.

Red Hat would like to thank halfdog for reporting CVE-2018-1000001. The CVE-2015-5180 issue was discovered by Florian Weimer (Red Hat Product Security).

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.5 Release Notes linked from the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

For the update to take effect, all services linked to the glibc library must be restarted, or the system rebooted.

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Virtualization Host 4 for RHEL 7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux for ARM 64 7 aarch64
• Red Hat Enterprise Linux for Power 9 7 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for IBM System z (Structure A) 7 s390x

Fixes

• BZ - 677316 - glibc: Increase number of search domains supported by /etc/resolv.conf
• BZ - 1175369 - CVE-2014-9402 glibc: denial of service in getnetbyname function
• BZ - 1249603 - CVE-2015-5180 glibc: DNS resolver NULL pointer dereference with crafted record type
• BZ - 1348000 - glibc: tst-malloc-usable spurious test failure
• BZ - 1349962 - Hide reference to mktemp in libpthread.
• BZ - 1349964 - Fix build warning in locarchive.c
• BZ - 1372305 - glibc: fopencookie hardening
• BZ - 1398413 - glibc: backport libio vtable hardening
• BZ - 1432085 - glibc: Detect and apply /etc/resolv.conf changes in libresolv
• BZ - 1435615 - nscd is not caching ldap netgroup data properly, hangs on nscd -i netgroup
• BZ - 1440250 - elf/check-localplt test fails with binutils 2.27
• BZ - 1443236 - Applications encounter SIGSEGV when LD_LIBRARY_PATH LD_LIBRARY_PATH contains only non-existings paths
• BZ - 1445644 - ifuncmod1.so ifuncmod3.so ifuncmod5.so tests fail during "make check" with binutils 2.27
• BZ - 1445781 - elf/tst-audit set of tests fails with error "no PLTREL found in object ld-linux-x86-64.so.2"
• BZ - 1447556 - glibc: malloc: check for chunk_size == next->prev->chunk_size in unlink
• BZ - 1448822 - glibc: Add definition of CLOCK_TAI
• BZ - 1452034 - when the /etc/hosts file has a line longer than 1028 characters getent ahostsv4 and ahostsv6 will stop working.
• BZ - 1463692 - glibc: Incorrect pointer alignment in NSS group merge result construction
• BZ - 1468807 - glibc: Support broken applications which call __tls_get_addr with an unaligned stack (GCC bug workaround)
• BZ - 1471111 - stackguard (CVE-2017-1000366) number not found in glibc changelog
• BZ - 1477529 - CVE-2017-12132 glibc: Fragmentation attacks possible when EDNS0 is enabled
• BZ - 1482988 - glibc: Remove noip6dotint support from the stub resolver
• BZ - 1484034 - glibc: Stricter IPv6 address parser
• BZ - 1504804 - CVE-2017-15670 glibc: Buffer overflow in glob with GLOB_TILDE
• BZ - 1505298 - CVE-2017-15804 glibc: Buffer overflow during unescaping of user names with the ~ operator
• BZ - 1508895 - glibc: Update built-in system call name list
• BZ - 1527904 - glibc: PTHREAD_STACK_MIN is too small on x86-64
• BZ - 1528418 - glibc: Merge error in XSAVE dynamic linker trampoline patch
• BZ - 1529982 - glibc: recompile glibc to fix incorrect CFI information on i386
• BZ - 1533836 - CVE-2018-1000001 glibc: realpath() buffer underflow when getcwd() returns relative path allows privilege escalation

CVEs

• CVE-2014-9402
• CVE-2015-5180
• CVE-2017-12132
• CVE-2017-15670
• CVE-2017-15804
• CVE-2018-1000001

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://access.redhat.com/documentation/en-US/red_hat_enterprise_linux/7/html/7.5_release_notes/index.html