The need to analyze the patch for MS16-030 recently presented itself to us due to some related product research. After the analysis was complete, we realized that the attack surface of the patch was pretty interesting and determined it may be beneficial to share part of the analysis. This post will focus on triggering a patched bug from MS16-030.
Security researchers with Vectra Threat Labs recently uncovered a critical vulnerability affecting all versions of Microsoft Windows reaching all the way back to Windows 95. The vulnerability allows an attacker to execute code at system level either over a local network or the Internet. As a result, attackers could use this vulnerability both to infect an end-user from the Internet, and then spread through the internal network.
Vectra and Microsoft collaborated during the investigation of this issue, and Microsoft has delivered a fix as part of Security Bulletin MS16-087, which is available here.
The vulnerabilities, CVE-2016-3238 (MS16-087), and CVE-2016-3239, stem from the way users connect to printers in the office and over the Internet. This vulnerability could enable a relatively unsophisticated attacker to incorporate IoT devices as part of an attack and quickly infiltrate and spread through a network without detection. While this blog provides an overview of the vulnerability, you can read the in-depth technical analysis here. In addition, a video summary of the vulnerability is available here.
The vulnerability in question centers around the ways that network users find and use printers on a network. Needless to say, modern organizations often have many users, and likewise often have many different makes and models of printers. Users expect to connect to and use whatever printer is most convenient, and likewise, mobile users expect to be able to come in to the office and print.