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R7-2017-02: Hyundai Blue Link Potential Info Disclosure (FIXED)

Blog Post created by todb Employee on Apr 25, 2017

Summary

Due to a reliance on cleartext communications and the use of a hard-coded decryption password, two outdated versions of Hyundai Blue Link application software, 3.9.4 and 3.9.5 potentially expose sensitive information about registered users and their vehicles, including application usernames, passwords, and PINs via a log transmission feature. This feature was introduced in version 3.9.4 on December 8, 2016, and removed by Hyundai on March 6, 2017 with the release of version 3.9.6.

Affected versions of Hyundai Blue Link mobile application upload application logs to a static IP address over HTTP on port 8080. The log is encrypted using a symmetrical key, "1986l12Ov09e", which is defined in the Blue Link application (specifically, C1951e.java), and cannot be modified by the user.

Once decoded, the logs contain personal information, including the user's username, password, PIN, and historical GPS data about the vehicle's location. This information can be used to remotely locate, unlock and start the associated vehicle.

This vulnerability was discovered by Will Hatzer and Arjun Kumar, and this advisory was prepared in accordance with Rapid7's disclosure policy.

Product Description

The Blue Link app is compatible with 2012 and newer Hyundai vehicles. The functionality includes remote start, location services, unlocking and locking associated automobiles, and other features, documented at the vendor's web site.

Credit

This vulnerability was discovered by independent researchers William Hatzer and Arjun Kumar.

Exploitation for R7-2017-02

The potential data exposure can be exploited one user at a time via passive listening on insecure WiFi, or by standard man-in-the-middle (MitM) attack methods to trick a user into connecting to a WiFi network controlled by an attacker on the same network as the user. If this is achieved, an attacker would then watch for HTTP traffic directed at an HTTP site at 54.xx.yy.113:8080/LogManager/LogServlet, which includes the encrypted log file with a filename that includes the user's email address.

It would be difficult to impossible to conduct this attack at scale, since an attacker would typically need to first subvert physically local networks, or gain a privileged position on the network path from the app user to the vendor's service instance.

Vendor Statement

Hyundai Motor America (HMA) was made aware of a vulnerability in the Hyundai Blue Link mobile application by researchers at Rapid7. Upon learning of this vulnerability, HMA launched an investigation to validate the research and took immediate steps to further secure the application. HMA is not aware of any customers being impacted by this potential vulnerability.

 

The privacy and security of our customers is of the utmost importance to HMA. HMA continuously seeks to improve its mobile application and system security. As a member of the Automotive Information Sharing Analysis Center (Auto-ISAC), HMA values security information sharing and thanks Rapid7 for its report.

Remediation

On March 6, 2017, the vendor updated the Hyundai Blue Link app to version 3.9.6, which removes the LogManager log transmission feature. In addition, the TCP service at 54.xx.yy.113:8000 has been disabled. The mandatory update to version 3.9.6 is available in both the standard Android and Apple app stores.

Disclosure Timeline

  • Tue, Feb 02, 2017: Details disclosed to Rapid7 by the discoverer.
  • Sun, Feb 19, 2017: Details clarified with the discoverer by Rapid7.
  • Tue, Feb 21, 2017: Rapid7 attempted contact with the vendor.
  • Sun, Feb 26, 2017: Vendor updated to v3.9.5, changing LogManager IP and port.
  • Mon, Mar 02, 2017: Vendor provided a case number, Consumer Affairs Case #10023339
  • Mon, Mar 06, 2017: Vendor responded, details discussed.
  • Mon, Mar 06, 2017: Version 3.9.6 released to the Google Play store.
  • Wed, Mar 08, 2017: Version 3.9.6 released to the Apple App Store.
  • Wed, Mar 08, 2017: Details disclosed to CERT/CC by Rapid7, VU#152264 assigned.
  • Wed, Apr 12, 2017: Details disclosed to ICS-CERT by Rapid7, ICS-VU-805812 assigned.
  • Fri, Apr 21, 2017: Details validated with ICS-CERT and HMA, CVE-2017-6052 and CVE-2017-6054 assigned.
  • Tue, Apr 25, 2017: Public disclosure of R7-2017-02 by Rapid7.
  • Tue, Apr 25, 2017: ICSA-17-115-03 published by ICS-CERT.
  • Fri, Apr 28, 2017: Redacted the now-disabled IP address for the LogManager IP address.

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