RHSA-2020:3861 - Security Advisory

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 Low. 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: LD_PREFER_MAP_32BIT_EXEC not ignored in setuid binaries (CVE-2019-19126)

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

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.9 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 Server - Extended Life Cycle Support 7 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 Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Virtualization Host 4 for RHEL 7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 1763325 - argp.h kills __attribute__, causing gcc 4.8.5 with -std=c++ results in compile / link errors for __gthrw_pthread_mutex_* functions
• BZ - 1772307 - glibc: Measured performance loss in lmbench for bcopy on Haswell processor
• BZ - 1774681 - CVE-2019-19126 glibc: LD_PREFER_MAP_32BIT_EXEC not ignored in setuid binaries
• BZ - 1775816 - glibc: Disable libio vtable validation for interposed pre-2.1 stdio handles [rhel-7]
• BZ - 1795573 - glibc: Remove problematic Obsoletes: from the spec file
• BZ - 1834816 - glibc: internal_end*ent in nss_compat may clobber errno, hiding ERANGE

CVEs

• CVE-2019-19126

References

• https://access.redhat.com/security/updates/classification/#low
• https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/7.9_release_notes/index