RHSA-2013:0124 - Security Advisory

Topic

Updated net-snmp packages that fix one security issue and multiple bugs are
now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team 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

These packages provide various libraries and tools for the Simple Network
Management Protocol (SNMP).

An out-of-bounds buffer read flaw was found in the net-snmp agent. A remote
attacker with read privileges to a Management Information Base (MIB)
subtree handled by the "extend" directive (in "/etc/snmp/snmpd.conf") could
use this flaw to crash snmpd via a crafted SNMP GET request.
(CVE-2012-2141)

Bug fixes:

• Devices that used certain file systems were not reported in the

"HOST-RESOURCES-MIB::hrStorageTable" table. As a result, the snmpd daemon
did not recognize devices using tmpfs, ReiserFS, and Oracle Cluster File
System (OCFS2) file systems. This update recognizes these devices and
reports them in the "HOST-RESOURCES-MIB::hrStorageTable" table.
(BZ#754652, BZ#755958, BZ#822061)

• The snmptrapd (8) man page did not correctly describe how to load

multiple configuration files using the "-c" option. This update describes
correctly that multiple configuration files must be separated by a comma.
(BZ#760001)

• Integers truncated from 64 to 32-bit were not correctly evaluated. As a

consequence, the snmpd daemon could enter an endless loop when encoding the
truncated integers to network format. This update modifies the underlying
code so that snmpd correctly checks truncated 64-bit integers. Now, snmpd
avoids an endless loop. (BZ#783892)

• snmpd did not correctly check for interrupted system calls when

enumerating existing IPv6 network prefixes during startup. As a
consequence, snmpd could prematurely exit when receiving a signal during
this enumeration. This update checks the network prefix enumeration code
for interrupted system calls. Now, snmpd no longer terminates when a signal
is received. (BZ#799699)

• snmpd used the wrong length of COUNTER64 values in the AgentX protocol.

As a consequence, snmpd could not decode two consecutive COUNTER64 values
in one AgentX packet. This update uses the correct COUNTER64 size and can
process two or mode COUNTER64 values in AgentX communication. (BZ#803585)

• snmpd ignored the "-e" parameter of the "trapsess" option in the snmpd

configuration file. As a result, outgoing traps were incorrectly sent with
the default EngineID of snmpd when configuring "trapsess" with an explicit
EngineID. This update modifies the underlying code to send outgoing traps
using the EngineID as specified in the "trapsess -e" parameter in the
configuration file. (BZ#805689)

• snmpd did not correctly encode negative Request-IDs in outgoing requests,

for example during trap operations. As a consequence, a 32-bit value could
be encoded in 5 bytes instead of 4, and the outgoing requests were refused
by certain implementations of the SNMP protocol as invalid. With this
update, a Request-ID can no longer become negative and is always encoded in
4 bytes. (BZ#818259)

• snmpd ignored the port number of the "clientaddr" option when specifying

the source address of outgoing SNMP requests. As a consequence, the system
assigned a random address. This update allows to specify both the port
number and the source IP address in the "clientaddr" option. Now,
administrators can increase security with firewall rules and
Security-Enhanced Linux (SELinux) policies by configuring a specific source
port of outgoing traps and other requests. (BZ#828691)

• snmpd did not correctly process responses to internal queries when

initializing monitoring enabled by the "monitor" option in the
"/etc/snmp/snmpd.conf" configuration file. As a consequence, snmpd was not
fully initialized and the error message "failed to run mteTrigger query"
appeared in the system log 30 seconds after the snmpd startup. This update
explicitly checks for responses to internal monitoring queries. (BZ#830042)

Users of net-snmp should upgrade to these updated packages, which contain
backported patches to correct these issues. After installing the update,
the snmpd and snmptrapd daemons 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/knowledge/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 755958 - net-snmp ignores reiserfs formatted partitions
• BZ - 803585 - agentx counter64 snmpget problem
• BZ - 815813 - CVE-2012-2141 net-snmp: Array index error, leading to out-of heap-based buffer read (snmpd crash)
• BZ - 840861 - snmpd does not report error when clientaddr <ip>:<port> cannot bind to the specified port

CVEs

• CVE-2012-2141

References

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