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Exploring the LogViewer in ServerDefender VP

Posted: November 15th, 2014 | Filed under: IIS & HTTP, Web and Application Security | Tags: , , , , , ,

Security You Can See

For the least few years, we have been developing ServerDefender VP, an advanced Web application firewall for IIS. One of the features that has been evolving along with ServerDefender VP is the LogViewer. This is the hub of the WAF where users can interact with and monitor malicious traffic hitting their site. Since there is so much to do within the LogViewer it sometimes becomes easy for a feature or two to be missed, so we’ve decided to explain some of the cool tricks its capable of.

What is the LogViewer?

The LogViewer is a tool that visualizes events (blocked threats and errors) that occur in your application and allows you take a variety of different actions on them with only a few clicks. When selecting an event users can see an array of data that pertains to it such as the referrer, user-agent, IP address, session ID, GET and POST data, and other critical information.

ServerDefender VP Web app firewall LogViewer

Click to enlarge.

What Can Actions Can I take on an Event?

There are several different actions that a user can take on an event in the LogViewer. The primary actions are for security settings (blocking IP addresses and creating exceptions), forensic tools (viewing all events by IP, comparing a session against IIS logs), and exporting reports.

ServerDefender VP LogViewer Actions

Click to enlarge.

Adding Exceptions

One of the key actions available to users from the LogViewer is the ability to add an exception to event, such as a false positive. Adding an exception on an event lets users specify new settings should the same event occur. This means that users can tell a blocked action to be allowed and configure new rules for the future.

ServerDefender VP Input Exception

Click to enlarge.


The LogViewer’s forensic tools enable users to gain further knowledge about an event and the session and IP behind it.

“View This Session in IIS Logs” displays the session logs with errors recorded by ServerDefender VP highlighted. This feature is useful to determine what occurred in a session prior to an error occurring and establishing the validity of an error, should there be any questions around it.

“View this IP Only” displays only the events in the LogViewer attributed to that IP address. This makes it easier to visualize the actions of a single IP address and understand its patterns, which can help users determine if the action they should take against the IP, if any.

Questions for Us? Ready to try?

The LogViewer is a powerful tool for viewing malicious traffic in your app and way to quickly react to events. If there’s anything else you’d like to learn about the LogViewer – or ServerDefender VP in general –  send us an email at or Tweet us @port80software. If you’d like to enjoy a 30-day free trial, go ahead and download now.

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Patch Now: Schannel Vulnerability Poses Huge Threat

Posted: November 13th, 2014 | Filed under: IIS & HTTP

A critical vulnerability in Microsoft Schannel headlined the security bulletin released by Microsoft for November. The vulnerability is the latest in TLS vulnerabilities for 2014, and means that every major TLS stack has been impacted by a severe vulnerability this year alone, as reported by Ars Technica. The Schannel vulnerability is drawing comparisons to Heartbleed, as it similarly allows for remote code execution and data theft.

Needless to say, it is imperative that affected systems are patched immediately.

Microsoft Security Bulletin MS14-066 – Critical – Find & Install Patch

Secure Channel, also known as Schannel, is the standard security package used by SSL/TLS in Windows. The Schannel vulnerability impacts all versions of Windows dating back to Vista/Windows Server 2003.

After the Bash and Poodle Vulnerabilities earlier this year, we should not be surprised to see a vulnerability that has gone unpatched for an extended period of time. This vulnerability just underscores the fact that even very mature software may have serious bugs from time to time.

The complete November security bulletin can viewed here.

Looking for more details about the Schannel vulnerability (MS14-066)? Read More

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How Your HTTP Errors Are Helping Hackers

Posted: October 23rd, 2014 | Filed under: Web and Application Security

What Errors Are

Error messages are a fairly standard part of the web that can provide useful information to developers to resolve issues or indicate to users that there is something wrong with a page. While smart developers and site admins will customize error messages to hide sensitive info, sometimes something as simple as a careless change to a configuration  file can expose verbose  HTTP errors - including 500-level errors that can contain normally-hidden details of your application. While this is okay for your developers to see – in order to resolve the error – these are not okay for external users to see.

Scenarios in Which You Might See an Error

Of course, errors are not desirable. Errors are more like the ugly blemish that haunt every app at some point and some are more serious than others. Detailed errors can provide contextual information pertaining to things like the server’s directory structure, the SQL queries being run, or the modules and libraries loaded by the application framework. By generating an error response, a hacker now has context for what creates a particular error state and also gains a little bit of extra knowledge about the site.

Why is This Useful?

Even seemingly unimportant or small bits of information can be very useful. With enough time and patience a hacker can use the initial leakage of information to probe further. Based on the knowledge gained from the initial error, they can dig deeper to see what other errors they can elicit. Much like a detective following a lead from a piece of evidence, a hacker can follow the knowledge gained from a piece of information to it’s conclusion. In all likelihood, they’ll come across another valuable piece of information via an error (if errors are completely unsuppressed) which will lead them down another path to explore and investigate. All this probing really puts a site at risk, as it increases the chances that a vulnerable piece of software (plugin, library, framework, etc.) is discovered. If a hacker can pinpoint that you’re using version A of X library with Y known vulnerability, then there is a very clear path to exploitation and causing serious damage.

Recon for Attack – Just like Real War

“Know your enemy” wrote Sun Tzu in the  Art of War, and most would agree that it’s unwise to launch an attack on a target without doing some reconnaissance to find points of weakness and points of strength. This principle applies to web technologies as well. Hackers can use error messages to probe and determine areas of weakness within their target. Giving hackers the ability to create errors without penalty is incredibly valuable as it gives them free reign to scout your site and gear up for attack. If areas of weakness or vulnerability are found during the scouting process, then the site can be added to a list of vulnerable sites, which then can be attacked by others in the community. If finding errors is the first line of attack, then hiding those errors should be the first line of defense. By preventing hackers from gathering accurate information about your site or app, you keep them from gaining an upper hand. Suppressing error messages is part of anti-reconnaissance and a solid defense-in-depth strategy.

An Internal Conflict

On the surface, detailed error messages can be useful for developers to debug issues. In fact, in many cases developers like these messages as it makes their jobs easier. Detailed messages often point right to the source of a problem, even indicating which line of code or which method is problematic and in which file. Just as this little snippet of information is invaluable to a developer doing some debugging, this information is useful to a hacker who is trying to cause trouble. Quickly, we can begin to see a conflict arising between a developer and a security professional:

  1. Dev wants detailed error messages in the app because this makes his/her life easier
  2. IT wants non-detailed error messages because this makes his/her life easier – and it protects the company
  3. Without detailed error messages, dev’s job becomes more difficult, and more time/company money is spent debugging code

While the sysadmin-developer divide is nothing new, this is a sensitive area because security is coming into play. That means that security should take precedence, but it doesn’t mean that developers’ jobs need be made more difficult.

Some interesting articles involving information leakage

Five Data Leak Nightmare OWASP on Information Leakage What is information leakage? 

Solution with ServerDefender VP

Luckily, this type of recon can be prevented and developers jobs don’t need to be made more difficult. Here at Port80, we spent a lot of time thinking of the best way keep verbose error details out of the hands of hackers. The solution we came up with is very simple: don’t show verbose error messages. Over the last few years we’ve developed a complete web application firewall called ServerDefender VP that offers the ability to handle errors. We developed methods to handle errors in two ways:

  1. Spot and prevent verbose 500 HTTP errors from being outwardly displayed
  2. Mask all errors with a generic error message, so all errors will look the same to would-be hackers

We also included the ability to whitelist IP addresses. This means that if a developer needs to debug something, the sysadmin can add their IP to a list of excluded IPs. This tells ServerDefender VP to let those IP addresses bypass the error handling controls, therefore allowing users to browse the site without error messages being suppressed.

How does it work?

These capabilities are default features in ServerDefender VP and are powerful ways to prevent reconnaissance. Here’s what happens when ServerDefender VP encounters a 5xx HTTP error:

  • User browses to a page
  • An HTTP error is caused and generated
  • ServerDefender VP catches the response before it’s posted
  • Instead of showing the HTTP error status code, SDVP sends a generic error response.  This can be not only a page that discloses no sensitive data, but even a response code that is normalized so that nothing can be inferred from it (e.g., 404 instead of 500).
  • The end user now knows something went wrong, and can even be shown a helpful site-customized experience to get them back on track, but not specifically what

This error message can be customized to be anything, but most importantly it ensures that no valuable reconnaissance information is leaked; the error is suppressed by ServerDefender VP and never sent to the client. This error handling technique takes away the first line of attack and means that hackers won’t be able to find clues that make it easier for them to hack you. We’ll leave you with one more piece of advice from Sun-Tzu, that sums up SDVP’s attitude toward data-hugry hackers: “Be extremely mysterious..thereby you can be the director of the opponent’s fate.

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POODLE SSL 3.0 Vulnerability: What it is and how to deal with it

Posted: October 17th, 2014 | Filed under: IIS & HTTP


from our friends at Net-Square

A Vulnerability known as POODLE, an acronym for Padding Oracle On Downgraded Legacy Encryption, is making headlines this week. The bug is a vulnerability in the design of SSL version 3.0, which is more than 15 years. However, SSL 3.0 is still widely supported, and nearly 97% of SSL servers are likely to be vulnerable to the bug, according to an October Netcraft Survey.

SSL v3.0 Vulnerable Servers


This vulnerability allows an attacker to intercept plaintext data from secure connections. Since SSLv3 has been quiet famous in the last 15 years it has put literally millions of browsers in jeopardy. As the chart above indicates, this is a vulnerability that has a sweeping impact.

How it happens?

Though users are upgrading to latest SSL versions (TLS 1.0, 1.1, 1.2), many TLS versions are backward compatible with SSL 3.0, hence when web browsers fail at connecting on these newer SSL version (i.e. TLS 1.0, 1.1, or 1.2), they may fall back to the older SSL 3.0 connection for a smooth user experience.

The other possibility is, a user is forced to step down to SSL 3.0. If an attacker has successfully performed a Man In The Middle attack MITM and causes connection failures, including the failure of TLS 1.0/1.1/1.2 connections. They can force the use of SSL 3.0 and then exploit the poodle bug in order to decrypt secure content transmitted between a server and a browser. Due to this down shift of the protocol the connection becomes vulnerable to the attack, eventually exploiting and intercepting user’s private data.

Google’s Bodo Möller, Thai Duong, and Krzysztof Kotowicz published the complete security advisory which can be found on

Possible remediation

To avoid falling prey to attackers exploiting POODLE, avoiding the use of public Wi-Fi hotspots, if user is sending valuable information (using online banking, accessing social networks via a browser, etc.), and noting this is always a risk, but the Poodle vulnerability makes it even more dangerous.

The other recommendation is disabling SSL v3 and all previous versions of the protocol in your browser settings and also on the server side will completely avoid it.  SSL v3 is 15 years old now and has been superseded by the more up-to-date and widely supported TSL protocol, supported by most modern web browsers.

DigitCert published a detailed step-by-step guide for disabling SSL 3.0.

Richard Burte also shared the command lines to disable SSL 3.0 on GitHub.

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Zero-Day Vulnerability (CVE-2014-4114) in Windows Server Exploited by Russian Espionage Group “Sandworm”

Posted: October 14th, 2014 | Filed under: IIS & HTTP, Web and Application Security


A Russian espionage group is exploiting a zero-day vulnerability in Windows Server 2008 and 2012, iSIGHT Partners reported on Tuesday. Microsoft is currently working on a patch for the vulnerability (CVE-2014-4114), but a number of targets have already been hit.

When exploited, this vulnerability allows an attacker to remotely execute arbitrary code, but requires a specially crafted file and use of social engineering to convince a user to open the file. iSIGHT noted specifically that PowerPoint files were used to exploit the vulnerability.

While there are specific targets that have been named, iSIGHT is also quick to point out that the visibility of the attack is limited and there is potential for broader targeting beyond this group of targets. The known targets include:

  • NATO
  • Ukranian government organizations
  • A Western European government organization
  • Energy sector firms (specifically in Poland)
  • European telecommunications firms
  • An United States academic organization

The team behind the attacks was dubbed the “Sandworm Team,” based on encoded references in command and control URLs and malware samples that refer to the sci-fi series Dune. iSIGHT reported that it has been monitoring the Sandworm Team since late 2013, and believes they were formed sometime in 2009.

Geopolitical Tensions Creating Targets

The takeaway here seems to be that the attacks do not only target governmental entities. The Sandworm Team has instead targeted entities that are geopolitically relevant in a broader sense: energy, telecommunications, education.

This should serve as a sign of potential threats to come. Private sector businesses that are strategically sensitive in a geopolitical sense might be on some state’s list of targets. This means organizations that share information with, provide services to, or provide infrastructure utilized by governmental organizations may be at risk. State-sponsored attacks will focus on targets with strategic significance which can range from obvious ones like power grids and financial institutions to less obvious targets like research universities.

State-sponsored attacks are on the rise and the targets are becoming broader. Organizations who align themselves with sensitive entities should have a heightened sense of awareness and look to raise their defenses if needed.

We will update this post accordingly as the story continues to develop.

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