RHSA-2011:1534 - Security Advisory

Topic

Updated nfs-utils packages that fix two security issues, various bugs, and
add one enhancement are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having low
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

Description

The nfs-utils packages provide a daemon for the kernel Network File System
(NFS) server, and related tools such as the mount.nfs, umount.nfs, and
showmount programs.

A flaw was found in the way nfs-utils performed IP based authentication of
mount requests. In configurations where a directory was exported to a group
of systems using a DNS wildcard or NIS (Network Information Service)
netgroup, an attacker could possibly gain access to other directories
exported to a specific host or subnet, bypassing intended access
restrictions. (CVE-2011-2500)

It was found that the mount.nfs tool did not handle certain errors
correctly when updating the mtab (mounted file systems table) file. A local
attacker could use this flaw to corrupt the mtab file. (CVE-2011-1749)

This update also fixes several bugs and adds an enhancement. Documentation
for these bug fixes and the enhancement will be available shortly from the
Technical Notes document, linked to in the References section.

Users of nfs-utils are advised to upgrade to these updated packages, which
contain backported patches to resolve these issues and add this
enhancement. After installing this update, the nfs service will be
restarted automatically.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 692702 - rpc.idmapd sometimes fails to start due to sunrpc
• BZ - 697975 - CVE-2011-1749 nfs-utils: mount.nfs fails to anticipate RLIMIT_FSIZE
• BZ - 702273 - Cannot umount NFS mount containing spaces
• BZ - 715078 - update exports(5) manpage with details about ipv6 configuration
• BZ - 716949 - CVE-2011-2500 nfs-utils: Improper authentication of an incoming request when an IP based authentication used
• BZ - 720479 - nfs-utils-1.2.3 breaks svcgssd - incorrectly orders libraries when built from source
• BZ - 723438 - rpc.mountd can segfault with showmount - REFERENCE TO PATCH THAT FIXES THIS
• BZ - 729001 - Debug file missing in debuginfo package for a binary
• BZ - 747400 - RHEL 6.2 beta rpcdebug has no flag for pNFS debug

CVEs

• CVE-2011-1749
• CVE-2011-2500

References

• https://access.redhat.com/security/updates/classification/#low
• https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.2_Technical_Notes/nfs-utils.html#RHSA-2011-1534