Most consumers are aware that when you close a credit card account, it’s not really closed. For “convenience” reasons, recurring subscription charges such as your cable bill will continue to be approved. You can kind of see where the credit card companies are coming from, but it’s a pretty weak argument. The cable company just needs to notify me that the credit card on file is no longer valid, and I’ll update my information. Problem solved.

But that credit card weirdness is nothing compared to the one I’m about to describe.

Before we do that, let’s take a moment to discuss the design principle of failing securely. The general idea is that if a security mechanism fails, it should fail closed. If your firewall crashes, it should block all traffic, not allow all the packets through. If the power source to your card key system is interrupted, it shouldn’t unlock all the doors. If the connection between your application server and your LDAP directory is severed, subsequent authentication requests should be rejected, not approved. This is not rocket science.

So back to credit cards. I had a conversation last night with an old friend who related a bizarre situation they had encountered during the QA process for one of their web applications. One of their tests involved repeatedly attempting a credit card transaction using a canceled/expired American Express card. Here’s what they saw in their logs, paraphrased by me:

Attempt 1: Denied
Attempt 2: Denied
Attempt 3: Denied
 .
 .
 .
Attempt 49: Denied
Attempt 50: Denied
Attempt 51: Approved

What the…? Approved? That can’t be right. So they ran the test again. Every time, after multiple consecutive rejected attempts, the transaction would inexplicably go through. The threshold wasn’t always 50, but the general pattern was consistent — keep trying and eventually it’ll work. Clearly, this had to be a bug in the code, but a deep-dive into the guts of the application turned up nothing. The application security group got American Express on the phone to see if they had any insight on this odd behavior. The answer? They didn’t concede the failure was on their end, despite log data showing the successful authorization codes.

My gut instinct would be that the application requesting the transactions wasn’t failing securely (e.g. network connection to AmEx timed out, so just approve the transaction). But that explanation wouldn’t account for authorization codes coming back.

So what in the world is going on here? Why would the system behave this way? Is it by design? I can’t think of a single legitimate use case for failing open like this. If this is actually a design decision by the credit card companies, I have no doubt that someone in our audience knows the rest of the story.

First we had the Gov. Palin Yahoo email break in to teach us the vulnerabilities of weak password reset schemes. Now we have a Joe the Plumber government records snooper teaching us about proper computer account management.

The Columbia Dispatch is reporting that a state employee with access to a “test account” has been accessing Joe the Plumber’s government records:

“We’re trying to pinpoint where it came from,” she said. The investigation could become “criminal in nature,” she said. Brindisi would not identify the account that pulled the information on Oct. 16.

Records show it was a “test account” assigned to the information technology section of the attorney general’s office, said Department of Public Safety spokesman Thomas Hunter.

Brindisi later said investigators have confirmed that Wurzelbacher’s information was not accessed within the attorney general’s office. She declined to provide details. The office’s test accounts are shared with and used by other law enforcement-related agencies, she said.

Security best practices require that test accounts be removed before a system is put into production and loaded with real data. Otherwise there is no accountability to any one individual. Shared accounts such as test accounts are frequently abused so that the snooper can get away undetected. The investigation should look at what other data has been snooped on using this test account. Perhaps this has been going on for a long time and no one noticed.

It is still likely that the perpetrator can be tracked down if he or she accessed the data from an internal system and the records application logged the IP address that connected to it. Even if the IP address doesn’t connect back to an individual’s computer and to a shared machine, the search will have been narrowed down greatly.

There is apparently a bit of fear going around information security circles that the next big trend in the disclosure wars is going to be “Partial Disclosure”. In the past, the vulnerability research community has embraced the concepts of “Full Disclosure” and/or “Non-Disclosure”. Once those concepts had been sufficiently played out, the general consensus was to move towards “Responsible Disclosure” whereby the security researcher responsibly discloses the discovered vulnerability to the vendor and works in a cooperative fashion in an effort to minimize the risk to the general user populous. This has worked well in the vast majority of cases that I have had the pleasure of managing the disclosure process.

Partial Disclosure – The Good

The responsible disclosure process tends to break down in rare occasions where the vendor doesn’t want to fix the issue. When this occurs, the researcher is put into a difficult position whereby full disclosure could put users’ systems at high risk of compromise. The other case where partial disclosure becomes an alternative is when the researcher has discovered a design flaw in a protocol or underlying multiple vendor component. Examples of this case include the DNS flaws published this past summer by Dan Kaminsky and the TCP denial of service condition discovered by Robert E. Lee and Jack Louis that is currently in the disclosure process. When the flaw affects a very large number of vendors and the actual problem is located within the underlying protocols that support the communications of the Internet as a whole, one possible solution is to follow a partial disclosure model where phasing the details to the general public can be used to encourage adoption and creation of patches throughout the enormous target audience.

Partial Disclosure – The Bad

What is driving the fear surrounding partial disclosure is the potential for abuse. When a major flaw is partially disclosed, a number of potential issues may occur. First and foremost, the further along the partial disclosure path we are, the more details will be released to the public, and the higher the probability that someone (either good or bad intentioned) will figure out the exploit and disclose the details. Second, when partially disclosing, the vendor’s hand is being forced into a situation that could speed up fixes, reduce testing, and cause ripple problems elsewhere within the infrastructure. It is difficult enough to dance the fine time line when doing responsible disclosure, but if we are escalated to the point of partial disclosure, additional fuel is added to the fire.

The Ugly

The real ugly part of partial disclosure is when we add to the equation the ability to spread fear, uncertainty, and doubt into the normal user community. It is generally well accepted that FUD can be used to drive additional revenue. If it is possible to increase the perceived magnitude of the “problem” that your product or service solves, it is possible to directly impact the demand for that product or service. That is the major fear imposed by the growing trend of partial disclosure. By releasing just enough information to trigger wide scale speculation into the flaw, it is possible to create buzz and garner media attention resulting in a lot of speculation and very little hard facts around the issue. The potential for abuse by the security industry at large is enormous.

The Fix

Some have suggested a group of security researchers be convened to vet the requirement of partial disclosure and to allow for independent peer review of any security research that requires the partial disclosure process. This suggestion leaves questions regarding who would stand on this group and who would be impartial enough to ensure that the right thing was always done regardless of profit potential. It also leaves open the opportunity for member researchers to utilize the information gathered during the vetting process to position themselves to profit from the data upon release. It might be wiser to rely on a higher level authority or government entity to manage this process and use the services of security researchers as required for subject matter expertise. While a group of this type wouldn’t ensure that all partial disclosure is appropriate, it would hopefully limit the potential for abuse and the ever present chance that people try to profit from the FUD that surrounds the current partial disclosure process.

Welcome, come on in, have a seat. There is a cold beer in the fridge, help yourself!

I may be new to the team, but I’m (reasonably) old to the game. My name is Tyler Shields and I’m the latest addition to the Veracode research team. I started at Veracode in September 2008 as a Senior Security Researcher and have been immediately thrown into the fire. Working for a fast paced, highly energetic company like Veracode, keeps you busy and challenges you every day. I plan to blog on the most interesting pieces of my work with Veracode and hope that you find it enlightening or at the very least entertaining.

In the past I have worked as the security engineer at a .com startup, as an incident response and forensics specialist for the United States Postal Service (think HUGE network), and most recently as a security consultant for @stake and Symantec. I have consulted on engagements for Fortune 500 companies, most major financial institutions, and the highest levels of the United States government. As a consultant my focus was on anything related to application security including, application penetration assessments, product security assessments, secure development lifecycle consulting, and secure application architecture engagements. I lead the @stake/Symantec Application Security Center of Excellence that was used to help guide the knowledge of the global consulting team. I also spent time as the lead for the Symantec Vulnerability Research program in which a number of interesting vulnerabilities were discovered and publicly released. In my spare time I enjoy reverse engineering and malware research. I recently completed my graduate degree in Information Security/Computer Science from James Madison University in Virginia.

So… Here’s to a new job, a new blog poster, and of course lots of fun to come.