Vulnerabilities / Threats
7/30/2009
01:17 AM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%
Repost This

Black Hat: PKI Hack Demonstrates Flaws in Digital Certificate Technology

Researcher Dan Kaminsky illuminates flaws in X.509 authentication

BLACK HAT USA -- LAS VEGAS -- The spotlight here this week was on another potentially broken piece of the Internet infrastructure as renowned white-hat hacker Dan Kaminsky today revealed critical bugs in the X.509 authentication scheme.

Kaminsky, who rocked the security community last year with his major DNS flaw find, said the potential for an X.509 meltdown and major hack is high, but not likely possible for at least another six months. "You can wait for it to blow up, or do something about it," says Kaminsky, director of penetration testing for IOActive. "This time, I don't want to see anything get 'owned.'"

Ironically, Kaminsky himself today was recovering from a targeted attack on his Website, email and Twitter accounts by a group of black hat hackers who stole passwords, emails, instant message chats from Kaminsky and former hacker Kevin Mitnick, and posted the information online. Kaminsky dismissed the attack "as nothing technically interesting" and likely began with a Web-borne exploit, he says.

Around 60 percent of attacks are due to weak or default passwords. "X.509 was supposed to be the solution" in authentication, Kaminsky says. "Businesses have spent hundreds of millions of dollars of investment in it. But there are things wrong structurally and technically with X.509." X.509 doesn't scale well, he says, and it can't delegate authority to issue certificates, for instance.

He noted that one of VeriSign's core root servers until recently used the older and weaker MD2 hash algorithm to sign certificates. "If a certificate is signed with MD2, it can accept everything," he says.

VeriSign no longer uses MD2 to sign any of its digital certificates, says Tim Callan, vice president of product marketing at VeriSign. "Last year, VeriSign implemented a process for transitioning off MD2 and, as of May 17th, the transition to the SHA-1 algorithm has been completed," he says.

Even so, browsers today still come with legacy [MD2] root certificates, Kaminsky says. "VeriSign's fix is to give new browsers something to ship. Microsoft, et al, are about making the old browsers ignore MD2 even if it is there. Both paths are helpful," he says.

Meanwhile, Kaminsky pointed to the work of another researcher who presented at Black Hat, Moxie Marlinspike, who demonstrated an attack that spoofs SSL certificates by adding a "null" string character to the certificate fields to fake out the browser. Moxie also added this null-termination attack to an existing hacking tool he developed.

"This is a wonderful example of what I'm talking about," Kaminsky says. "Moxie and I have the same core attack here -- he did this year what I did last year. We both went for the null" string attack, he says. Moxie was able to force a Firefox browser to download a code "update" over SSL with his phony digital certificate, Kaminsky says.

VeriSign's Callan says none of VeriSign's certificate brands or sub-bands have a domain containing a null character. "Marlinspike's presentation underscores the importance of such stringent issuance practices by CAs to ensure the integrity of online security," Callan says.

Ultimately, the answer is to move to DNSSEC, Kaminsky says. "We're going to have the DNS root signed [by DNSSEC] by the end of the year, so then we can build a new PKI with exclusion and delegation" capabilities, he says.

"Today, Dan Kaminsky revealed more important research that will surely serve to raise awareness on the need for ongoing enhancements to Internet infrastructure standards," VeriSign's Callan says.

Have a comment on this story? Please click "Discuss" below. If you'd like to contact Dark Reading's editors directly, send us a message. Kelly Jackson Higgins is Senior Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise Magazine, ... View Full Bio

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2012-3946
Published: 2014-04-24
Cisco IOS before 15.3(2)S allows remote attackers to bypass interface ACL restrictions in opportunistic circumstances by sending IPv6 packets in an unspecified scenario in which expected packet drops do not occur for "a small percentage" of the packets, aka Bug ID CSCty73682.

CVE-2012-5723
Published: 2014-04-24
Cisco ASR 1000 devices with software before 3.8S, when BDI routing is enabled, allow remote attackers to cause a denial of service (device reload) via crafted (1) broadcast or (2) multicast ICMP packets with fragmentation, aka Bug ID CSCub55948.

CVE-2013-6738
Published: 2014-04-24
Cross-site scripting (XSS) vulnerability in IBM SmartCloud Analytics Log Analysis 1.1 and 1.2 before 1.2.0.0-CSI-SCALA-IF0003 allows remote attackers to inject arbitrary web script or HTML via an invalid query parameter in a response from an OAuth authorization endpoint.

CVE-2014-0188
Published: 2014-04-24
The openshift-origin-broker in Red Hat OpenShift Enterprise 2.0.5, 1.2.7, and earlier does not properly handle authentication requests from the remote-user auth plugin, which allows remote attackers to bypass authentication and impersonate arbitrary users via the X-Remote-User header in a request to...

CVE-2014-2391
Published: 2014-04-24
The password recovery service in Open-Xchange AppSuite before 7.2.2-rev20, 7.4.1 before 7.4.1-rev11, and 7.4.2 before 7.4.2-rev13 makes an improper decision about the sensitivity of a string representing a previously used but currently invalid password, which allows remote attackers to obtain potent...

Best of the Web