RHSA-2012:0796 - Security Advisory

Topic

Updated rsyslog packages that fix one security issue, multiple bugs, and
add two enhancements are now available for Red Hat Enterprise Linux 6.

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

The rsyslog packages provide an enhanced, multi-threaded syslog daemon.

A numeric truncation error, leading to a heap-based buffer overflow, was
found in the way the rsyslog imfile module processed text files containing
long lines. An attacker could use this flaw to crash the rsyslogd daemon
or, possibly, execute arbitrary code with the privileges of rsyslogd, if
they are able to cause a long line to be written to a log file that
rsyslogd monitors with imfile. The imfile module is not enabled by default.
(CVE-2011-4623)

Bug fixes:

• Several variables were incorrectly deinitialized with Transport Layer

Security (TLS) transport and keys in PKCS#8 format. The rsyslogd daemon
aborted with a segmentation fault when keys in this format were provided.
Now, the variables are correctly deinitialized. (BZ#727380)

• Previously, the imgssapi plug-in initialization was incomplete. As a

result, the rsyslogd daemon aborted when configured to provide a GSSAPI
listener. Now, the plug-in is correctly initialized. (BZ#756664)

• The fully qualified domain name (FQDN) for the localhost used in messages

was the first alias found. This did not always produce the expected result
on multihomed hosts. With this update, the algorithm uses the alias that
corresponds to the hostname. (BZ#767527)

• The gtls module leaked a file descriptor every time it was loaded due to

an error in the GnuTLS library. No new files or network connections could
be opened when the limit for the file descriptor count was reached. This
update modifies the gtls module so that it is not unloaded during the
process lifetime. (BZ#803550)

• rsyslog could not override the hostname to set an alternative hostname

for locally generated messages. Now, the local hostname can be overridden.
(BZ#805424)

• The rsyslogd init script did not pass the lock file path to the 'status'

action. As a result, the lock file was ignored and a wrong exit code was
returned. This update modifies the init script to pass the lock file to
the 'status' action. Now, the correct exit code is returned. (BZ#807608)

• Data could be incorrectly deinitialized when rsyslogd was supplied with

malformed spool files. The rsyslogd daemon could be aborted with a
segmentation fault. This update modifies the underlying code to correctly
deinitialize the data. (BZ#813079)

• Previously, deinitialization of non-existent data could, in certain error

cases, occur. As a result, rsyslogd could abort with a segmentation fault
when rsyslog was configured to use a disk assisted queue without specifying
a spool file. With this update, the error cases are handled gracefully.
(BZ#813084)

• The manual page wrongly stated that the '-d' option to turn on debugging

caused the daemon to run in the foreground, which was misleading as the
current behavior is to run in the background. Now, the manual page reflects
the correct behavior. (BZ#820311)

• rsyslog attempted to write debugging messages to standard output even

when run in the background. This resulted in the debugging information
being written to some other output. This was corrected and the debug
messages are no longer written to standard output when run in the
background. (BZ#820996)

• The string buffer to hold the distinguished name (DN) of a certificate

was too small. DNs with more than 128 characters were not displayed. This
update enlarges the buffer to process longer DNs. (BZ#822118)

Enhancements:

• Support for rate limiting and multi-line message capability. Now,

rsyslogd can limit the number of messages it accepts through a UNIX socket.
(BZ#672182)

• The addition of the "/etc/rsyslog.d/" configuration directory to supply

syslog configuration files. (BZ#740420)

All users of rsyslog are advised to upgrade to these updated packages,
which upgrade rsyslog to version 5.8.10 and correct these issues and add
these enhancements. After installing this update, the rsyslog daemon 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 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 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 i386
• 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 - 740420 - Add a /etc/rsyslog.d config directory
• BZ - 769822 - CVE-2011-4623 rsyslog: DoS due integer signedness error while extending rsyslog counted string buffer
• BZ - 803550 - rsyslog fails to initialize gtls driver because of too many open files
• BZ - 813079 - rsyslog segfaults attempting to read a malformed / old format spool file
• BZ - 813084 - rsyslog segfaults when configured with disk queue with non-existent (unnamed) spool file
• BZ - 820311 - Manpage: rsyslogd does the fork in debug mode while manpage says otherwise
• BZ - 820996 - rsyslog writes debug messages to fd 1 even after forking

CVEs

• CVE-2011-4623

References

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