Red Hat Enterprise Linux v5.4 has been released and available via RHN for immediate update. The new version includes the kernel-based virtual machine (KVM) virtualization, next generation of developer features and tools including GCC 4.4, a new malloc(). Also included clustered, high-availability filesystem to support Microsoft Windows storage needs on Red Hat Enterprise Linux.
[continue reading…]
BIND 9 is an implementation of the Domain Name System (DNS) protocols. named daemon is an Internet Domain Name Server for UNIX like operating systems. Dynamic update messages may be used to update records in a master zone on a nameserver. When named receives a specially crafted dynamic update message an internal assertion check is triggered which causes named to exit. An attacker which can send DNS requests to a nameserver can cause it to exit, thus creating a Denial of Service situation. configuring named to ignore dynamic updates is NOT sufficient to protect it from this vulnerability. This exploit is public. Please upgrade immediately.
[continue reading…]
Fedora Linux version 11 has been released and available for download ( jump to download link ). Fedora Linux is a community-based Linux distribution. Fedora is sponsored by Red Hat, Inc.
One of Fedora’s main objectives is not only to contain free and open source software, but also to be on the leading edge of such technologies.
Fedora 11, codenamed “Leonidas”, was released on June 9, 2009. The features include ext4, a 20-second startup, and the latest GNOME, KDE and XFCE releases. Firefox 3.5 and Thunderbird 3’s latest pre-releases are available as well.
[continue reading…]
The Blue Screen of Death (BSoD) is used by Microsoft Windows, after encountering a critical system error. Linux / UNIX like operating system may get a kernel panic. It is just like BSoD. The BSoD and a kernel panic generated using a Machine Check Exception (MCE). MCE is nothing but feature of AMD / Intel 64 bit systems which is used to detect an unrecoverable hardware problem. MCE can detect:
FreeBSD is just plain old good UNIX with rock solid networking stack. It is quite popular amongst hosting companies, ISPs, portals (such as Yahoo) and a few large financial institutions because of its reliability, robustness and performance.
A new version of the FreeBSD is scheduled for release next week (4-May-2009). A beta 2 was made available for download few weeks ago for final round of testing before the official launch.
[continue reading…]
Geolocation software is used to get the geographic location of visitor using IP address. You can determine country, organization and guess visitors location. This is useful for
a] Fraud detection
b] Geo marketing and ad serving
c] Target content
d] Spam fighting
e] And much more.
mod_geoip is a Lighttpd module for fast ip/location lookups. In this tutorial you will learn about mod_geoip installation and php server side examples to determine visitors country.
[continue reading…]
This is an user contributed article.
Linux computer console is a physical device to operate a computer / server. Here are few steps which, if taken, make it more difficult for an attacker to quickly modify a system from its console.
[continue reading…]
The tail command is one of the best tool to view log files in a real time using tail -f /path/to/log.file syntax on a Unix-like systems. The program MultiTail lets you view one or multiple files like the original tail program. The difference is that it creates multiple windows on your console (with ncurses). This is one of those dream come true program for UNIX sys admin job. You can browse through several log files at once and do various operations like search for errors and more.
[continue reading…]
Vsftpd supports virtual users with PAM (pluggable authentication modules). A virtual user is a user login which does not exist as a real login on the system in /etc/passwd and /etc/shadow file. Virtual users can therefore be more secure than real users, because a compromised account can only use the FTP server but cannot login to system to use other services such as ssh or smtp.
[continue reading…]
Recently, I noticed that the timeout values differ on CentOS v5.x and RHEL Linux 5.x guests on VMWare ESX4 and ESX3.5. I’ve notices that older ESX 3.5 set a 60 secs timeout and ESX4.x set to 180 secs. Luckly you can fix it easily:
Edit /etc/udev/rules.d/99-vmware-scsi-udev.rules,
# vi /etc/udev/rules.d/99-vmware-scsi-udev.rules
Sample config:
RUN+="/bin/sh -c 'echo 180 >/sys$DEVPATH/device/timeout'"
Find timeout value (180) and change it as per your requirements. Make sure you install the vmware-tools RPM.
