Security on your mind?
Protect your home and business networks with the free, community version of EnGarde Secure Linux. Don't rely only on a firewall to protect your network, because firewalls can be bypassed. EnGarde Secure Linux is a security-focused Linux distribution made to protect your users and their data.
The security experts at Guardian Digital fortify every download of EnGarde Secure Linux with eight essential types of open source packages. Then we configure those packages to provide maximum security for tasks such as serving dynamic websites, high availability mail, transport, network intrusion detection, and more. The result for you is high security, easy administration, and automatic updates.
The Community edition of EnGarde Secure Linux is completely free and open source. Updates are also freely available when you register with the Guardian Digital Secure Network.
Guardian Digital Makes Email Safe For Business - Microsoft 365, Goo....
Security Compromise Underway?
Spotting a security compromise under way can be a tense undertaking. How you react can have large consequences.
If the compromise you are seeing is a physical one, odds are you have spotted someone who has broken into your home, office or lab. You should notify your local authorities. In a lab, you might have spotted someone trying to open a case or reboot a machine. Depending on your authority and procedures, you might ask them to stop, or contact your local security people.
If you have detected a local user trying to compromise your security, the first thing to do is confirm they are in fact who you think they are. Check the site they are logging in from. Is it the site they normally log in from? No? Then use a non-electronic means of getting in touch. For instance, call them on the phone or walk over to their office/house and talk to them. If they agree that they are on, you can ask them to explain what they were doing or tell them to cease doing it. If they are not on, and have no idea what you are talking about, odds are this incident requires further investigation. Look into such incidents , and have lots of information before making any accusations.
If you have detected a network compromise, the first thing to do (if you are able) is to disconnect your network. If they are connected via modem, unplug the modem cable; if they are connected via Ethernet, unplug the Ethernet cable. This will prevent them from doing any further damage, and they will probably see it as a network problem rather than detection.
If you are unable to disconnect the network (if you have a busy site, or you do not have physical control of your machines), the next best step is to use something like tcp_wrappers or ipfwadm to deny access from the intruder's site.
If you can't deny all people from the same site as the intruder, locking the user's account will have to do. Note that locking an account is not an easy thing. You have to keep in mind .rhosts files, FTP access, and a host of possible backdoors.
After you have done one of the above (disconnected the network, denied access from their site, and/or disabled their account), you need to kill all their user processes and log them off.
You should monitor your site well for the next few minutes, as the attacker will try to get back in. Perhaps using a different account, and/or from a different network address.
From the Linux Security HowTo by Dave Wreski:
/howtos
LinuxSecurity.com Feature Extras:
EnGarde Secure Linux v3.0.6 Now Available - Guardian Digital is happy to announce the release of EnGarde Secure Community 3.0.6 (Version 3.0, Release 6). This release includes several bug fixes and feature enhancements to the Guardian Digital WebTool and the SELinux policy, several updated packages, and a couple of new packages available for installation.
Linux File & Directory Permissions Mistakes - One common mistake Linux administrators make is having file and directory permissions that are far too liberal and allow access beyond that which is needed for proper system operations. A full explanation of unix file permissions is beyond the scope of this article, so I'll assume you are familiar with the usage of such tools as chmod, chown, and chgrp. If you'd like a refresher, one is available right here on linuxsecurity.com.
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Thank you for reading the LinuxSecurity.com weekly security newsletter. The purpose of this document is to provide our readers with a quick summary of each week's most relevant Linux security headline.
| Debian | ||
| Debian: New awstats packages fix arbitrary command execution | ||
| 26th, May, 2006
Updated package. advisories/debian/debian-new-awstats-packages-fix-arbitrary-command-execution-97479 |
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| Debian: New lynx packages fix denial of service | ||
| 26th, May, 2006
Updated package. advisories/debian/debian-new-lynx-packages-fix-denial-of-service |
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| Debian: New tiff packages fix denial of service | ||
| 27th, May, 2006
Updated package. advisories/debian/debian-new-tiff-packages-fix-denial-of-service |
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| Debian: New MySQL 4.0 packages fix several vulnerabilities | ||
| 29th, May, 2006
Updated package. advisories/debian/debian-new-mysql-40-packages-fix-several-vulnerabilities |
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| Debian: New dovecot packages fix directory traversal | ||
| 29th, May, 2006
Updated package. advisories/debian/debian-new-dovecot-packages-fix-directory-traversal |
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| Debian: New libextractor packages fix arbitrary code execution | ||
| 29th, May, 2006
Updated package. advisories/debian/debian-new-libextractor-packages-fix-arbitrary-code-execution-60012 |
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| Debian: New Linux kernel 2.4.17 packages fix several vulnerabilities | ||
| 29th, May, 2006
Updated package. advisories/debian/debian-new-linux-kernel-2417-packages-fix-several-vulnerabilities |
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| Debian: New motor packages fix arbitrary code execution | ||
| 31st, May, 2006
Updated package. advisories/debian/debian-new-motor-packages-fix-arbitrary-code-execution |
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| Debian: New typespeed packages fix arbitrary code execution | ||
| 31st, May, 2006
Niko Tyni discovered a buffer overflow in the processing of network data in typespeed, a game for testing and improving typing speed, which could lead to the execution of arbitrary code. advisories/debian/debian-new-typespeed-packages-fix-arbitrary-code-execution |
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| Debian: New lynx-cur packages fix several vulnerabilities | ||
| 1st, June, 2006
Updated package. advisories/debian/debian-new-lynx-cur-packages-fix-several-vulnerabilities |
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| Mandriva | ||
| Mandriva: Updated netpbm packages fix crash issues with some converters | ||
| 26th, May, 2006
The pnmtopalm program, part of netpbm, crashes on many images. The pnmtofits program, part of netpbm, crashes during conversion. Updated packages have been patched to correct these issues. |
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| Mandriva: Updated mpg123 packages fix DoS vulnerability. | ||
| 26th, May, 2006
An unspecified vulnerability in mpg123 0.59r allows user-complicit attackers to trigger a segmentation fault and possibly have other impacts via a certain MP3 file, as demonstrated by mpg1DoS3. Packages have been patched to correct this issue. |
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| Mandriva: Updated dia packages fix string format vulnerabilities. | ||
| 30th, May, 2006
A format string vulnerability in Dia allows user-complicit attackers to cause a denial of service (crash) and possibly execute srbitrary code by triggering errors or warnings, as demonstrated via format string specifiers in a .bmp filename. NOTE: the original exploit was demonstrated through a command line argument, but there are other mechanisms inputs that are automatically process by Dia, such as a crafted .dia file. (CVE-2006-2480) Multiple unspecified format string vulnerabilities in Dia have unspecified impact and attack vectors, a different set of issues than CVE-2006-2480. (CVE-2006-2453) Packages have been patched to correct this issue. |
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| SuSE | ||
| SuSE: foomatic-filters shellcode injection | ||
| 30th, May, 2006
A bug in cupsomatic/foomatic-filters that allowed remote printer users to execute arbitrary commands with the UID of the printer daemon has been fixed (CVE-2004-0801). |
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| SuSE: cron local privilege escalation | ||
| 31st, May, 2006
The code in do_command.c in Vixie cron does not check the return code of a setuid call, which might allow local users to gain root privileges if setuid fails in cases such as PAM failures or resource limits. This problem is known to affect only distributions with Linux 2.6 kernels, but the package was updated for all distributions for completeness. This problem is tracked by the Mitre CVE ID CVE-2006-2607. |
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| SuSE: kernel (SUSE-SA:2006:028) | ||
| 31st, May, 2006
Multiple vulnerabilities have been fixed in the linux kernel. |
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| SuSE: rug (SUSE-SA:2006:029) | ||
| 31st, May, 2006
Updated package. |
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