Last week there was some discussion in the #snort IRC channel about why Debian distributes such an ancient version of Snort, namely version 2.3.3. This release is more than 2 years old and no longer supported by SourceFire. The snort.org website says about the old versions:
You should not use these unless you really know what you are doing. Many bugs may have been fixed, including remote vulnerabilities
Even though Debian is able to fix any security bugs themselves, and they don’t need to rely on SourceFire for this, Snort 2.3.3 is still going to be inferior to the recent 2.6.1.5. Why? Well recent Snort versions have many more and improved detection options, such as a better pattern matcher, defragmentation preprocessor, improved stream preprocessor, smtp plugin, etc, etc.
So why is Debian not updating Snort? The answer can be found in the Debian bugtracker. Snort is released under the GPL and up to and including version 2.3.3 included a ruleset. But since then only Snort itself is distributed under the GPL, the (VRT) rules are now under a less free license. Of course the user can get them for free, but with a 30 day delay and only after registering with SourceFire. Big deal, I would say, just remove the rules from the package and put some doc describing how to get rules. But the Debian maintainer doesn’t like this idea:
“Consequently, upgrading to 2.4 would mean providing just an IDS engine, not an IDS “service”.” (source)
I think this reasoning makes no sense, for a number of reasons:
- Snort can be useful even without any rules: it can detect anomalies in stream tracking, dns, ftp, http, smtp. It can provide statistics, capture traffic.
- Managing the Snort rules through the very static Debian packages system make no sense in the first place. Many of the rules change weekly or even daily. Debian would never update the package for this. Oinkmaster should be used for this, and Debian provides this tool as well.
- People can write their own rules.
- There still are many free rules available. The Snort community rules are GPL licensed, Bleeding rules are BSD licensed. Together they have thousands of rules.
So Debian, please make your Snort package usable again, and update it to the latest stable version! And while you are at it, provide an inline enabled package as well 
Removing Trac ticket comment spam in Debian Lenny
Friday, April 23rd, 2010The Vuurmuur website runs Trac and overall I’m pretty happy with it. The only thing that Trac doesn’t do well, is dealing with spammers. Spammers target Trac a lot, so that’s a real problem.
To prevent spammers from making it through, I run Scallywhack and a number of custom ModSecurity rules. So far, spams only made it through as new tickets in the ticket tracker, so I installed the TicketDeletePlugin.
Yesterday, I saw the first spam as a comment to an existing and valid ticket. Like tickets themselves, ticket comments can not be removed by Trac by default. Luckily, upstream Trac seems to have fixed this. I’m running Debian’s version of Trac 0.11.1 however, so I decided to patch that. The patches in the Trac ticket #454 didn’t apply cleanly, so I had to patch it manually. To save others the work, it’s available here: http://www.inliniac.net/files/trac_0.11.1-debian-comment_edit.patch
To use it, make a copy of your /usr/share/pyshared/trac directory.
Next, go into the trac directory and run the command:
patch -p1 < /path/to/trac_0.11.1-debian-comment_edit.patch
After this, each comment in the comment system will have a “edit” button and you can remove the spam message content. It’s not possible to remove the entire comment, but this works for me.
Tags: comment spam, Debian, trac
Posted in Debian, ModSecurity | No Comments »