Moderate: rsyslog (SL6)

Synopsis: Moderate: rsyslog security, bug fix, and enhancement update
Issue Date: 2012-06-20
CVE Numbers: CVE-2011-4623

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.

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.

* 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.

* 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)


* Support for rate limiting and multi-line message capability. Now,
rsyslogd can limit the number of messages it accepts through a UNIX socket.

* 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.


– Scientific Linux Development Team