web site security

When Defenses are Offensive

November 1, 2017 Web Site SecurityBill PenningtonLeave a comment

Cory Doctrow has a good article on the differences between the speed of detected an attack and the automated response to it and the slowness in recovering from a mis-applied block.

As usual Cory outlines it is brilliantly simple, straight forward terms that anyone can understand. I used this tactic quite a bit when pen-testing in a no-holds bar pen-test. Basically I spoofed UDP based attacks against a host and used the central log servers IP address as the source of the attack. This triggered the HIDS on this host to block traffic to and from the log server. Instant invisibility from the folks monitoring the central log server.

This also realy drives home my issue with auto-blocking web application firewalls.  When your WAF decides to block something one from using your website the really have no recourse that will respond as fast as the blocking of there traffic. If Mr. O’Reilly can’t checkout, he will just move along to someplace he can.

When you deploy any mechanism that auto-blocks traffic you must take great care to think through the methods of blocking, the thresholds where something is blocked, and how to recover from inadvertent blocking of a legitimate person/host.

Apple Blocks the Word Script

October 13, 2017 Web Site SecurityBill PenningtonLeave a comment

Jordan Weins post about the exact problem with offensive defense systems on his blog How Not to protect your webap. Great job Apple, the word “script” is so evil I can’t do a search for Applescript. So would argue this is a good thing, especially if they have seen any of the Applescript I have written. This smells like someone who does not understand Web Application Security, specifically cross site scripting, created a rule to block the one bad vector they could think of, while not thinking through the impact of that rule. Now if someone could just import that rule onto the MS website maybe we could rid the world of VBScript.

SANS says the #1 Server Security Issue is Your Web Application

September 4, 2017 Web Site SecurityBill Pennington1 Comment

The latest SANS Top 20 has been released and according to SANS the #1 issue impacting the security of your servers is the web application code that lives on top of it.

I agree with them (in a totally biased way of course) but the data they cite leaves me with an uneasy feeling. SANS likes to go by reported vulnerabilities. Reporting of web application vulnerabilities is basically non-existent outside of open source PHP applications. Every once in a while you will see a reported vulnerability in something like PeopleSoft or MS Sharepoint but a large percentage of the reported web application vulnerabilities are in things like Jim Bob’s PHP Guestbook 0.00001alpha and really who cares about that.

PHP include issues are most certainly bad but they are far from the most prevalent issue found in large enterprises. In our customer base we only have 22 PHP sites we scan out of around 650 sites today. There is just not a lot of PHP adoption in the enterprise, at least in our customer base.

So while I agree with the conclusion I feel leary about how it was reached.

5 Security Predictions for 2018

July 16, 2017 Web Site SecurityBill PenningtonLeave a comment

1. We will see the first multi-website XSS worm.

I think we will finally get a true cross site XSS work in 2008. Combining XSRFand XSS to propagate a worm across multiple sites and multiple domains. The first one will be benign but the others will be much more malicious in nature. Leading victim candidate are social network sites that are becoming increasingly open.

2. More consolidation in the security industry.

There is still a great difference between the small security players and the giant ones in terms of cash flow. As the old guard (McaFee, Symantec, etc) see dwindling revenue on various fronts they will begin to convert some of that pesky cash into acquisitions. Could this be the year Qualys gets gobbled up?

3. PCI will clarify section 6.6

This is more of a hope really. Since it goes into full effect mid-2008 I hope to see some clearer definitions around what companies are expected to do.

4. 2008 will set another record for breaches

Yeah big shocker! The trend will continue with more smaller breaches this year as opposed to a few massive ones.

5. RBN will disappear again. Someone related to them will get busted.

With the light too bright they will morph again and change tactics. Money will still flow in to them by the millions though. However with increasing public knowledge of the group someone will get busted and connected to them. No one high up in the group, but some poor sucker at the wrong place at the wrong time. Law Enforcement will trump it as a “significant” blow to the group. RBN won’t notice.

The Big Announcement

June 21, 2017 Web Site SecurityBill PenningtonLeave a comment

I’ve not been this pumped about something in a long time. Jeremiah actually has been pulling me into liking this idea for a very long time. I hated it at first. I mean WAFs, bleh. Plus I mean didn’t we already try scanners + WAFs before? Oh yeah the total trainwreck that was AVDL. So one thing I failed to realize was that Jeremiah’s approach is a bit different and when combined with WhiteHat Sentinel (aka NOT a scanner) it is a no brainer.

WAFs generally struggle in a few different areas, the people running them are not web app. security experts and trying to apply a default deny policy, while a great idea in theory, is pretty hard in the real world . There is just way to much movement in most applications to pin it down. Even if the app does not change frequently, WAF admins are very hesitant to even come close to blocking legitimate traffic. This is what was happening on this site that covers EMT stethoscopes, nursing stethoscopes, nursing student stethoscopes and general stethoscope reviews.

What really sold me though is when I saw it in action for the first time. From the Sentinel UI we clicked a button that updated the F5 with a rule to block a vulnerability. The rule is automatically generated based on the vulnerability. We then clicked the retest button and the vulnerability was no longer exploitable . Note my careful choice of words, exploitable VS. “not there anymore”. The vulnerability certainly still exist in the code but now that the attack is blocked the business can decide if this is a good enough solution or they need to go fix the actual flaw.

The geek in me is screaming that it still needs to be fixed, the business side is saying that the rule is good enough and I am not going to commit resources to fixing it until that code is worked on again. From the PCI Section 6.6 perspective this gives the business some great options. As our customers are becoming aware of the PCI requirements and the PCI auditors are becoming tougher on web application vulnerabilities we run into a difficult situation. PCI audit is coming up and the app. is riddled with vulnerabilities.  I now have to dedicate precious development resources to fix these vulnerabilities ASAP. With this solution I can apply this rules and effectively mitigate the issue.

I am pretty excited to be part of this. I think we have moved the industry forward today, even if it was just a small step. People now have some more options to mitigate risk besides running to the development team with yet another fire.

Source Mentioned: Best Stethoscope

FBI CSRF and Jail How to Get Someone Raided

April 2, 2017 Web Site SecurityBill PenningtonLeave a comment

This seems pretty scary. Apparently the FBI posted a link on some online forum that claimed to display kiddy porn. The story is here.

Upon reading this the first thing that popped into my mind was CSRF(Cross Site Request Forgery) Now this is not classic CSRF since CSRF generally implies I am exercising some functionality on the target site. I am using CSRF as a handy term for “if you visit a page I control content on I can make you request any other link I want”. Now remeber this is not only pages like this blog where I clearly control the content, but any other place I can provide links, usually to images. Social networking sites, forums, image hosting sites and even in email signatures.

This is an even better scam than the now famous 911 swatting scams. Now instead of SWAT busting in to rescue you the FBI bust in to arrest you. What great fun! It will be interesting to see how many of these stick. It seems to be based on some pretty flimsy evidenc. The article above points out that open wireless networks are just one way someone could fool the system. CSRF is better because your browser will actually go to the page and a forensics examination of your machine will show that you went there. Not a good position to be in in court with a jury and often times judge with no technical background at all.

Update from my buddy Zeno: The file that keeps track of places IE has been, index.dat, does not log refers and apparently that file and it’s contents have held up in court…

Free Dr. Pepper Overloads Site, Exposes Captcha Key

January 12, 2017 Web Site SecurityBill PenningtonLeave a comment

I love Dr. Pepper. So when then announced they where giving it away for free I was all over it.

Sadly though the site was not up to the task and was continually failing in new and wonderful ways. Everything from Service Unavailable to this piece of code poo:

Start ‘, gmdate(”F j, Y, g:i:s a T”, $start_time), ‘
Now ‘, gmdate(”F j, Y, g:i:s a T”, time()), ‘
End ‘, gmdate(”F j, Y, g:i:s a T”, $end_time), ‘
Time From Start ‘, $g_nTimeToStart, ‘ (H:’,$g_nHoursFromStart,’ M:’,$g_nMinutesFromStart,’ S:’,$g_nSecondsFromStart,’)’, ‘
Time Until End ‘, $g_nTimeToEnd, ‘ (H:’,$g_nHoursToEnd,’ M:’,$g_nMinutesToEnd,’ S:’,$g_nSecondsToEnd,’)’, $g_bSwitch? ‘
SWITCH
‘:’
NO SWITCH
‘; exit(); } require_once(’recaptchalib.php’); include “account/process_user.php”; // Get a key from http://recaptcha.net/api/getkey $publickey = “6Lcp6AMAAAAAACdUl5_X5cbuQLzgWMMRHlb3MbwV”; $privatekey = “6Lcp6AMAAAAAAGR1pjoXN2dLHg9sVIKmBR-XXXX”; ?>

Hey cool a private key (I changed it above)! It looks like to goes to ReCaptcha so I hop on over to the ReCaptcha site to find out how bad this is. I found this;

Signing up for a reCAPTCHA Key

In order to use reCAPTCHA, you need a public/private API key pair. This key pair helps to prevent an attack where somebody hosts a reCAPTCHA on their website, collects answers from their visitors and submits the answers to your site. You can sign up for a key on the reCAPTCHA Administration Portal.

So if you where paying attention you can now crack Dr. Peppers ReCaptcha all day long. This is not the end of the world but I am sure some spammer somewhere is already on in and doing something not good.

This is a great example of the type of things missed when you are only looking one piece of the app. sec. problem.  This could have been prevented with an egress filter of some sort or better load a failure testing in QA. It looks like the folks at Dr Pepper are doing neither.

And I never did get my free Dr. Pepper!!