![[ Screenshot: PHP Logo ]](https://perishablepress.com/wp/wp-content/images/2012/php-easter-eggs-02a.jpg)
A reader recently brought to my attention a reported vulnerability on servers running PHP. It’s been known about for eons, but it’s new to me and it involves easter eggs in PHP so I thought it would be fun to share a quick post about what it is and how to prevent leakage of sensitive information about your server. It only takes a moment to disable the easter-egg information, should you decide to do so. Continue reading »
![[ 6G Blacklist (beta) ]](https://perishablepress.com/wp/wp-content/images/2012/6G-Blacklist.png)
Since releasing the 5G Blacklist earlier this year, malicious server scans and bad requests have surged with more novel attacks than I’ve seen since first getting into this stuff six years ago. In other words, now is the time to beef up security and lock things down. If you’re into monitoring your server and knowing your traffic, you may be observing the same recent spike in malicious activity. In response to these attacks, I’ve been secretly working on the next […] Continue reading »
Working on the next version of the G-Series Blacklist, I needed a way to match a wide variety of UTF-8-encoded (hex) character strings. Those familiar with their site’s traffic will recognize this particular type of URI request string, which is typically associated with malicious server scanning, exploits, and other malicious behavior. As I explain in this post, pattern-matching and blocking the blank-space, or whitespace character in URL-requests is an effective way to improve the security of your website. Continue reading »
Cool trick that you may not have known about.. it’s possible to get case-insensitive matching with the powerful RedirectMatch directive. Normally, you would just write your redirect as something like this: Continue reading »
![[ Jeff Spicoli from Fast Times at Ridgemont High ]](https://perishablepress.com/wp/wp-content/images/2011/roll-your-own.jpg)
My current ISP likes to keeps things spicy by changing my IP address every few months or so. There are a million ways to get this changing IP information, but as an obsessive web developer, I like to roll my own whenever possible. That means using my own resources instead of spending time and energy elsewhere. So the goal for this project is to create a web page that does one thing very well: display the visitor’s current IP information. […] Continue reading »
![[ Ajax Error Log - File Structure ]](https://perishablepress.com/wp/wp-content/images/2011/ajax-error-log-files.png)
As an obsessive website administrator, I like to keep a keen eye on my error logs. Once a week, I download my PHP, 404, and other error logs, and analyze them as closely as time allows. Monitoring site errors and other traffic patterns leads to many of the security-related articles I post here at Perishable Press, including resources such as the 5G Blacklist, Ultimate HTAccess Blacklist, and the Blacklist Candidate Series. Easily, one of the best ways to protect your […] Continue reading »
After implementing Chris Coyier’s More Sidebar technique here at Perishable Press, I needed a good source of “filler” content for the “more” blocks. After experimenting with multiple loops and template tags, the idea of sliding in RSS feeds seemed like a better solution. Replacing some empty space with great content is a win-win for everyone. For example, I display a few of my recent tweets in the sidebar to help fill a lil’ space. It’s a great way to share […] Continue reading »
![[ Twitter Bird ]](https://perishablepress.com/wp/wp-content/images/2011/twitter-bird.png)
My previous theme displays my latest tweet at the top of every page. It turned out to be an excellent technique for getting more followers – visitors see the tweet, click the link, and possibly follow me on Twitter. There is even a cookie-powered “Hide” link for uninterested visitors to hide the tweet for awhile. I received quite a few requests for a tutorial on the technique, so here is how to display your latest tweet with show/hide cookies. For […] Continue reading »
I am in the process of migrating my sites from A Small Orange to Media Temple. Part of that process involves canonicalizing domain URLs to help maximize SEO strategy. At ASO, URL canonicalization required just a few htaccess directives: # enforce no www prefix <ifmodule mod_rewrite.c> RewriteCond %{HTTP_HOST} !^domain\.tld$ [NC] RewriteRule ^(.*)$ http://domain.tld/$1 [R=301,L] </ifmodule> When placed in the web-accessible root directory’s htaccess file, that snippet will ensure that all requests for your site are not prefixed with www. There’s […] Continue reading »
![[ Black Hole (Vector) ]](https://perishablepress.com/wp/wp-content/images/2010/blackhole/blackhole-01.jpg)
One of my favorite security measures here at Perishable Press is the site’s virtual Blackhole trap for bad bots. The concept is simple: include a hidden link to a robots.txt-forbidden directory somewhere on your pages. Bots that ignore or disobey your robots rules will crawl the link and fall into the honeypot trap, which then performs a WHOIS Lookup and records the event in the blackhole data file. Once added to the blacklist data file, bad bots immediately are denied […] Continue reading »
![[ WordPress ]](https://perishablepress.com/wp/wp-content/images/2009/misc-chunks/wordpress-logo-blue.png)
One of the most popular articles here at Perishable Press is my January 2005 post, Stupid htaccess Tricks. In that article, I bring together an extensive collection of awesome copy-&-paste HTAccess code snippets. Four years later, people continue to tell me how much they enjoy and use the content as a bookmarked reference for many of their HTAccess needs. The article was even published in a book on Joomla! Security. This is very inspiring to me, so I have decided […] Continue reading »
Running a private site is all about preventing unwanted visitors. Here is a quick and easy way to allow access to multiple IP addresses while redirecting everyone else to a custom message page. To do this, all you need is an HTAccess file and a list of IPs for which you would like to allow access. Continue reading »
Recently a reader asked about how to password-protect a directory for every specified IP while allowing open access to everyone else. In my article, Stupid htaccess Tricks, I show how to password-protect a directory for every IP except the one specified, but not for the reverse case. In this article, I will demonstrate this technique along with a wide variety of other useful password-protection tricks, including a few from my Stupid htaccess Tricks article. Before getting into the juicy stuff, […] Continue reading »
Normally, when visitors post a comment to your site, specific types of client data are associated with the request. Commonly, a client will provide a user agent, a referrer, and a host header. When any of these variables is absent, there is good reason to suspect foul play. For example, virtually all browsers provide some sort of user-agent name to identify themselves. Conversely, malicious scripts directly posting spam and other payloads to your site frequently operate without specifying a user […] Continue reading »
Just like last year, this Spring I have been taking some time to do some general maintenance here at Perishable Press. This includes everything from fixing broken links and resolving errors to optimizing scripts and eliminating unnecessary plugins. I’ll admit, this type of work is often quite dull, however I always enjoy the process of cleaning up my HTAccess files. In this post, I share some of the changes made to my HTAccess files and explain the reasoning behind each […] Continue reading »
Given my propensity to discuss matters involving error log data (e.g., monitoring malicious behavior, setting up error logs, and creating extensive blacklists), I am often asked about the best way to go about monitoring 404 and other types of server errors. While I consider myself to be a novice in this arena (there are far brighter people with much greater experience), I do spend a lot of time digging through log entries and analyzing data. So, when asked recently about […] Continue reading »
Perishable Press is operated by Jeff Starr, a professional web developer and book author with two decades of experience.
Here you will find posts about web development, WordPress, security, and more »
