Yahoo leaks private key, allows anyone to build Yahoo-signed Chrome extensions
Yahoo accidentally leaked the private key that was used to digitally sign its new Axis extension for Google Chrome
IDG News Service - Yahoo was forced to release a new version of its Axis extension for Google Chrome after the original one contained a private key that allowed anyone to digitally sign extensions in Yahoo's name.
Axis is a new search and browsing tool from Yahoo that was released on Wednesday. It is available for desktop computers, as an extension for Google Chrome, Mozilla Firefox, Internet Explorer and Safari, as well as for iOS devices, as a stand-alone app.
However, while looking at the source code for the Google Chrome Axis extension, hacker and security blogger Nik Cubrilovic discovered a serious security flaw -- the package included the private cryptographic key used by Yahoo to sign the extension.
"With access to the private certificate file [private key] a malicious attacker is able to create a forged extension that Chrome will authenticate as being from Yahoo," Nik Cubrilovic said in a blog post on Thursday.
Google Chrome extensions come packed as CRX files, which are essentially digitally signed ZIP-format archives.
Every CRX file contains a public key that's part of a private-public key pair unique to its creator. The private key is used to sign the extension, while the public key is used by the browser to verify the signature's authenticity.
Since private keys allow developers to digitally sign new extensions or update their old ones, they should always be kept secret.
In order to prove the implications of the private key leak, Cubrilovic created a proof-of-concept Chrome extension that displays an alert on every visited website and signed it with Yahoo's private key.
An attacker can push a Yahoo-signed malicious extension to a browser that has the Axis extension installed, by using techniques like DNS spoofing, Cubrilovic said.
Google Chrome automatically checks for extension updates by querying update URLs specified by developers. If attackers can forge the DNS (domain name system) responses received by the browser, they can force it to install a rogue digitally signed extension update from a server under their control.
Yahoo confirmed the security issue. "We worked quickly to resolve the issue and have issued a new Chrome plug-in," a Yahoo spokeswoman said via email. "Users who downloaded Yahoo! Axis on Chrome between the hours of 6-9 p.m. Pacific Time on May 23, 2012, are encouraged to uninstall the previous version and reinstall the new version at axis.yahoo.com."
- 15 Non-Certified IT Skills Growing in Demand
- How 19 Tech Titans Target Healthcare
- Twitter Suffering From Growing Pains (and Facebook Comparisons)
- Agile Comes to Data Integration
- Slideshow: 7 security mistakes people make with their mobile device
- iOS vs. Android: Which is more secure?
- 11 sure signs you've been hacked
- Pay-as-you-Grow Data Protection: IBM Tivoli's Full-featured Data Protection Suite for Small to Medium Businesses IBM Tivoli Storage Manager Suite for Unified Recovery gives small and medium businesses the opportunity to start out with only the individual solutions...
- Streamline Data Protection with IBM Tivoli Storage Manager Operations Center IBM Tivoli Storage Manager (TSM) has been an industry-standard data protection solution for two decades. But, where most competitors focus exclusively on Backup...
- Simplify and Consolidate Data Protection for Better Business Results Learn about IBM® Tivoli® Storage Manager Operations Center, which provides advanced visualization, built-in analytics and integrated workflow automation features that leapfrog traditional backup...
- HP HAVEn: See the big picture in Big Data HP HAVEn is the industry's first comprehensive, scalable, open, and secure platform for Big Data. Enterprises are drowning in a sea of data...
- Meg Whitman presents Unlocking IT with Big Data During this Web Event you will hear Meg Whitman, President and CEO, HP discuss HAVEn - the #1 Big Data platform, as well...
- The New Way to Work Knowledge Vault This Knowledge Vault focuses on how, in today's increasingly virtual world, it's more important than ever to engage deeply with employees, suppliers, partners,... All Desktop Apps White Papers | Webcasts