The Harry Callahan Postulate

What kind of weight do you put in different browser defenses?
– Process separation? Plugin isolation?
Origin header support?
– X-Frame-Options, X-XSS-Protection? Built-in reflected XSS protection? NoScript?
– Automatic patching? Anti-virus? Safe browsing lists?

Instead of creating a matrix to compare browsers, versions, and operating systems try adopting the Harry Callahan Postulate:

Launch your browser. Open one tab for your web-based e-mail, another for your online bank. Login to both. Then click on one of the shortened links below. Being as this is the world wide web, the most dangerous web in the world, and would blow your data clean apart, you’ve got to ask yourself one question: Do I feel lucky?

Well, do ya punk?

http://bit.ly/ddoHd8
http://bit.ly/A6Ca
http://bit.ly/wszWO
http://bit.ly/lSxst
http://bit.ly/OApJX
http://bit.ly/SAFEST

If you don’t feel safe, then you should reconsider your browsing habits or at least make an effort to bring your computer’s patch level up to date.

Factor of Ultimate Doom

Vulnerability disclosure presents a complex challenge to the information security community. A reductionist explanation of disclosure arguments need only present two claims. One end of the spectrum goes, “Only the vendor need know so no one else knows the problem exists, which means no one can exploit it.” The information-wants-to-be-free diametric opposition simply states, “Tell everyone as soon as the vulnerability is discovered”.

The Factor of Ultimate Doom (FUD) is a step towards reconciling this spectrum into a laser-focused compromise of agreement. It establishes a metric for evaluating the absolute danger inherent to a vulnerability, thus providing the discoverer with guidance on how to reveal the vulnerability.

The Factor is calculated by simple addition across three axes: Resources Expected, Protocol Affected, and Overall Impact. Vulnerabilities that do not meet any of the Factor’s criteria may be classified under the Statistically Irrelevant Concern metric, which will be explored at a later date.

Resources Expected
(3) Exploit doesn’t require shellcode; merely a JavaScript alert() call
(2) Exploit shellcode requires fewer than 12 bytes. In other words, it must be more efficient than the export PS1=# hack (to which many operating systems, including OS X, remain vulnerable)
(1) Exploit shellcode requires a GROSS sled. (A GROSS sled uses opcode 144 on Intel x86 processors, whereas the more well-known NOP sled uses opcode 0x90.)

Protocol Affected
(3) The Common Porn Interchange Protocol (TCP/IP)
(2) Multiple online rhetorical opinion networks
(1) Social networks

Overall Impact
(3) Control every computer on the planet
(2) Destroy every computer on the planet
(1) Destroy another planet (obviously, the Earth’s internet would not be affected — making this a minor concern)

The resulting value is measured against an Audience Rating to determine how the vulnerability should be disclosed. This provides a methodology for verifying that a vulnerability was responsibly disclosed.

Audience Rating (by Factor of Ultimate Doom*)
(> 6) Can only be revealed at a security conference
(< 6) Cannot be revealed at a security conference
(< 0) Doesn’t have to be revealed; it’s just that dangerous

(*Due to undisclosed software patent litigation, values equal to 6 are ignored.)