RHSA-2015:1385 - Security Advisory

Topic

Updated net-snmp packages that fix one security issue and several bugs are
now available for Red Hat Enterprise Linux 6.

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

Description

The net-snmp packages provide various libraries and tools for the Simple
Network Management Protocol (SNMP), including an SNMP library, an
extensible agent, tools for requesting or setting information from SNMP
agents, tools for generating and handling SNMP traps, a version of the
netstat command which uses SNMP, and a Tk/Perl Management Information Base
(MIB) browser.

A denial of service flaw was found in the way snmptrapd handled certain
SNMP traps when started with the "-OQ" option. If an attacker sent an SNMP
trap containing a variable with a NULL type where an integer variable type
was expected, it would cause snmptrapd to crash. (CVE-2014-3565)

This update also fixes the following bugs:

• The HOST-RESOURCES-MIB::hrSystemProcesses object was not implemented

because parts of the HOST-RESOURCES-MIB module were rewritten in an earlier
version of net-snmp. Consequently, HOST-RESOURCES-MIB::hrSystemProcesses
did not provide information on the number of currently loaded or running
processes. With this update, HOST-RESOURCES-MIB::hrSystemProcesses has been
implemented, and the net-snmp daemon reports as expected. (BZ#1134335)

• The Net-SNMP agent daemon, snmpd, reloaded the system ARP table every 60

seconds. As a consequence, snmpd could cause a short CPU usage spike on
busy systems with a large APR table. With this update, snmpd does not
reload the full ARP table periodically, but monitors the table changes
using a netlink socket. (BZ#789500)

• Previously, snmpd used an invalid pointer to the current time when

periodically checking certain conditions specified by the "monitor" option
in the /etc/snmpd/snmpd.conf file. Consequently, snmpd terminated
unexpectedly on start with a segmentation fault if a certain entry with the
"monitor" option was used. Now, snmpd initializes the correct pointer
to the current time, and snmpd no longer crashes on start. (BZ#1050970)

• Previously, snmpd expected 8-bit network interface indices when

processing HOST-RESOURCES-MIB::hrDeviceTable. If an interface index of a
local network interface was larger than 30,000 items, snmpd could terminate
unexpectedly due to accessing invalid memory. Now, processing of all
network sizes is enabled, and snmpd no longer crashes in the described
situation. (BZ#1195547)

• The snmpdtrapd service incorrectly checked for errors when forwarding a

trap with a RequestID value of 0, and logged "Forward failed" even though
the trap was successfully forwarded. This update fixes snmptrapd checks and
the aforementioned message is now logged only when appropriate.
(BZ#1146948)

• Previously, snmpd ignored the value of the "storageUseNFS" option in the

/etc/snmpd/snmpd.conf file. As a consequence, NFS drivers were shown as
"Network Disks", even though "storageUseNFS" was set to "2" to report them
as "Fixed Disks" in HOST-RESOURCES-MIB::hrStorageTable. With this update,
snmpd takes the "storageUseNFS" option value into account, and "Fixed Disks"
NFS drives are reported correctly. (BZ#1125793)

• Previously, the Net-SNMP python binding used an incorrect size (8 bytes

instead of 4) for variables of IPADDRESS type. Consequently, applications
that were using Net-SNMP Python bindings could send malformed SNMP
messages. With this update, the bindings now use 4 bytes for variables with
IPADRESS type, and only valid SNMP messages are sent. (BZ#1100099)

• Previously, the snmpd service did not cut values in

HOST-RESOURCES-MIB::hrStorageTable to signed 32-bit integers, as required
by SNMP standards, and provided the values as unsigned integers. As a
consequence, the HOST-RESOURCES-MIB::hrStorageTable implementation did not
conform to RFC 2790. The values are now cut to 32-bit signed integers, and
snmpd is therefore standard compliant. (BZ#1104293)

Users of net-snmp are advised to upgrade to these updated packages, which
contain backported patches to correct these issues.

Solution

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

For details on how to apply this update, refer to:

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

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 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 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 886468 - snmpd does not report error when clientaddr <ip>:<port> cannot bind to the specified port
• BZ - 967871 - net-snmp does not display correct lm_sensors sensor data / missing CPU cores
• BZ - 1023570 - libnetsnmpagent.so crash under certain conditions - patched upstream in 2009
• BZ - 1034441 - Net-SNMP libraries and headers are invalid due to hyphens.
• BZ - 1069046 - snmpd returns truncated value for Counter64 taken from smuxpeer
• BZ - 1070075 - SNMP HRPROCESSORLOAD RETURNS INCORRECT VALUES FOR PROCESSOR #'S > 100
• BZ - 1073544 - net-snmp.rpm is not multilib safe
• BZ - 1100099 - net-snmp-python adds zeros to end of IP address (IPADDR type), which is not valid
• BZ - 1119567 - After installation of net-snmp-devel-5.5-44.el6_4.4.x86_64 the command '$ man snmp_read' fails
• BZ - 1125155 - CVE-2014-3565 net-snmp: snmptrapd crash when handling an SNMP trap containing a ifMtu with a NULL type
• BZ - 1125793 - [RHEL6] net-snmp "storageUseNFS 2" option does not report NFS mount as "Fixed Disks"
• BZ - 1126914 - Ocetets Truncated with Python Bindings
• BZ - 1134335 - hrSystemProcesses is missing (net-snmp-5.5-49.el6_5.2)
• BZ - 1157373 - README file in net-snmp-python package is wrong
• BZ - 1181994 - net-snmp package does not compile on Fedora 21
• BZ - 1188295 - net-snmp snmpd fork() overhead [fix available]

CVEs

• CVE-2014-3565

References

• https://access.redhat.com/security/updates/classification/#moderate