, SecurityFocus 2007-03-01
ARLINGTON, VA. -- Security researcher David Maynor got some measure of vindication at the Black Hat DC Conference this year.
Six months after the security researcher and his colleague Jon Ellch claimed that Mac OS X wireless drivers were vulnerable to attack, Maynor on Wednesday revealed the code he used to exploit one of the native flaws the two researchers found in the platform as well as e-mails showing he notified Apple as to the danger.
Maynor said he found three flaws: one in the driver for the Atheros wireless chip--used in MacBooks, another in the Broadcom wireless chip--the hardware under the hood of many PowerBooks, and a third in the Bluetooth driver (corrected). However, Maynor only showed e-mail messages that he sent and received from his personal .Mac account, which limited the evidence shown at the conference to the Broadcom flaw, he said.
In an e-mail dated August 9 to Apple from the account, Maynor promised the company that his demo at the Black Hat Las Vegas 2006 Conference would not reveal the flaw in the native drivers, but use a third-party card, because the pair of researchers had not fully identified all the platforms affected by the bugs.
"Don't freak out," wrote Maynor, who is now the chief technology officer at startup Errata Security. "Although it is using a Mac, we are not sharing a native exploit. There are native exploits, but we are still determining how many other platforms are affected."
The flaws affected not only Mac OS X, but any platform that used drivers based on the Broadcom and Atheros reference driver, he said. While MacBooks and PowerBooks were affected, so were Dell laptop running Windows XP. Apple fixed the flaws on September 21, but did not give Maynor or Ellch credit. The Atheros flaw could have allowed a remote attacker to compromise a vulnerable MacBook or PowerBook remotely via an overly long service set identifier (SSID), the label used to identify an access point.
Ellch was not present at the Black Hat DC Conference.
Apple did not immediately respond to requests for comment about the claims. However, in September, the company told reporters that the researchers did not send them information on the flaws, an assertion refuted by the e-mail evidence shown by Maynor.
"They did not supply us with any information to allow us to identify a specific problem, so we initiated an internal audit," Apple spokesman, Anuj Nayar told Macworld. "Todays update preemptively strengthens our drivers against potential vulnerabilities, and while it addresses issues found internally by Apple, we are open to hearing from security researchers on how to improve security on the Mac."
The events underscored that the issues surrounding the disclosure of software flaws have not yet been hammered out. Apple has often been criticized by researchers for not working well with flaw finders. The company is not the only one attempting to gag researchers: Another security researcher presenting on flaws in radio-frequency identification (RFID) proximity badges at the Black Hat DC Conference had to severely curtail his presentation, after security firm HID Global threatened possible legal action.
According to e-mails showed during Maynor's session, Apple's later assertions that he and Ellch shared no information with the company and that the researchers changed their story were both incorrect. On August 15, Apple sent Maynor a blog entry to post on his site in his own name, disavowing the existence of any threat to Apple's laptops from the flaw, Maynor claimed. He showed an e-mail from Apple to his .Mac account that supported the allegations.
Maynor and Ellch refused to talk about the issue because Apple had gagged the researchers by brandishing legal threats at Maynor's previous employer SecureWorks, the researcher said.
"Apple released patches, while at the same time threatening SecureWorks with a lawsuit," he said.
Apple likely made the mistakes out of a lack of experience in dealing with security issues, said Jeff Moss, director of the Black Hat Conference.
"It seems to be the new players who have no experience are causing the problems," Moss said. "Apple is where Microsoft was six years ago. At this point, they don't even have a CSO (chief security officer)."
For his part, Maynor plans to continue researching Apple flaws, but will no longer report the issues to the company.
"I no longer feel comfortable engaging in any type of relationship with the company and I will not report any future findings to them," Maynor said.
Maynor plans to post all of the documents and personal correspondence with Apple on Errata Security's blog.
CORRECTION: The article mistakenly attributed only a single flaw to Maynor and Ellch. While Maynor only showed evidence regarding the Broadcom flaw at the conference, he stated that he also found flaws in the Atheros drivers used by MacBooks under Mac OS X 10.4.6 and Bluetooth drivers.