Author: Preston St. Pierre
released for ruby, rsync, kdelibs, mysql, acroread, Tomcat, glibc, spamassassin,
qt3, ftpd, Netscape, the Linux kernel. The distributors include Debian, Fedora,
Gentoo, Mandrake, NetBSD, Red Hat, SuSE, and Trustix.
Using swatch for log analysis
With most services, when
anything slightly significant happens, a message about it is reported to syslogd.
The sooner the user is aware of the message, the sooner the user can take action
in regard to that message if it is needed. With 1000+ long log files, log checkers
are needed as time savers and to make sure an indication of trouble is not missed.
Swatch stands for Simple
WATCHer. Other log analysis software scans the logs periodically, they can tell
you what HAS happened. Swatch can do this, but it can also actively scan log
entries as syslogd gets them and tell you what IS happening. Not only this,
swatch can also take actions when it encounters certain log messages.
First, download the newest version of swatch. Then, run:
After swatch is installed,
perl modules that are needed for use of swatch may also have to be downloaded.
Swatch uses regular expressions
to find lines of interest. Once swatch finds a line that matches a pattern,
it takes an action, such as printing it to the screen, emailing it, or taking
a user defined action.
exec "/etc/call_pager 5551234 08"
This is an example of a
section of a swatch configuration script. First, swatch looks for a line that
contains the word denied, Denied, or anything that starts with DEN and ends
with ED. Once it finds a line that contains one of the three search strings,
it echoes the line in bold into the terminal and makes the bell sound (^G) 3
times. Then, swatch emails the user that is running swatch (usually root) about
the line and executes the /etc/call_pager program with the given options. ignore
/sendmail/,/fax/,/unimportant stuff/ In this example, the search strings sendmail,
fax, and unimportant stuff are going to be ignored, even if they would normally
match one of the strings being looked for.
Using swatch is very simple.
For using swatch to check logs normally, run:
swatch --config-file=/home/chris/swatch.conf --examine=/var/log/messages
This is assuming that the
configuration file for swatch is located at /home/chris/swatch.conf and that
the file that is to be checked in called /var/log/messages. To use swatch as
a constantly running service that scans lines of a log file as they come in,
swatch --config-file=/home/chris/swatch.conf --tail-file=/var/log/messages
Security Tip Written
by Chris Parker (firstname.lastname@example.org)
Additional tips are available at the following URL:
Interview with Gary McGraw, Co-author of Exploiting Software: How to Break Code
– Gary McGraw is perhaps best known for his groundbreaking work on securing software,
having co-authored the classic Building Secure Software (Addison-Wesley, 2002).
More recently, he has co-written with Greg Hoglund a companion volume, Exploiting
Software, which details software security from the vantage point of the other
side, the attacker. He has graciously agreed to share some of his insights with
all of us at LinuxSecurity.com.
Expert Dave Wreski Discusses Open Source Security – Dave Wreski,
CEO of Guardian Digital, Inc. and respected author of various hardened security
and Linux publications, talks about how Guardian Digital is changing the face
of IT security today. Guardian Digital is perhaps best known for their hardened
Linux solution EnGarde Secure Linux, touted as the premier secure, open-source
platform for its comprehensive array of general purpose services, such as web,
FTP, email, DNS, IDS, routing, VPN, firewalling, and much more.
Linux Advisory Watch is
a comprehensive newsletter that outlines the security vulnerabilities that have
been announced throughout the week. It includes pointers to updated packages
and descriptions of each vulnerability.[
This can lead an attacker who has also shell access to the webserver to
The rsync developers have discoverd a security related problem in rsync
temporary file vulnerability
This can be abused by a local attacker to create or truncate arbitrary files
temporary file vulnerability
Jeroen van Wolffelaar discovered an insecure temporary file vulnerability
This update backports a security fix to a path-sanitizing flaw that affects
Acroread contains two errors in the handling of UUEncoded filenames that
Improper file ownership may allow a member of the tomcat group to execute
glibc contains an information leak vulnerability allowing the debugging
This vulnerability could allow the listing of arbitrary files and allow
Buffer overflow vulnerability
An attacker may construct a carefully-crafted playlist file which will cause
Format string vulnerability
An attacker may be able to execute arbitrary code as the user running courier-imapd
If rsync is running in daemon mode, and not in a chrooted environment, it
of service vulnerability
Security fix prevents a denial of service attack open to certain malformed
| Heap overflow
his vulnerability could allow for the compromise of the account used to
A set of flaws in the ftpd source code can be used together to achieve root
Netscape Navigator and Netscape Communicator have been removed from the
of service vulnerability
A bug in the SoundBlaster 16 code which did not properly handle certain
If rsync is running in daemon-mode and without a chroot environment it is
Chris Evans found a heap overflow in the BMP image format parser which can
| Path escape
Please either enable chroot or upgrade to 2.6.1. People not running a daemon,