Microsoft has corrected 27 critical vulnerabilities this Patch Tuesday, including a Microsoft .Net Framework flaw that is being actively exploited to install Finspy surveillance software on devices running Windows 10.
Microsoft .Net Framework Flaw Exploited by ‘Multiple’ Actors
Finspy is legitimate software developed by the UK-based Gamma Group, which is used by governments around the world for cyber-surveillance. The software has been installed in at least two attacks in the past few months according to FireEye researchers, the latest attack leveraged the Microsoft .Net Framework flaw.
The attack starts with a spam email containing a malicious RTF document. The document uses the CVE-2017-8759 vulnerability to inject arbitrary code, which downloads and executes a VB script containing PowerShell commands, which in turn downloads the malicious payload, which includes Finspy.
FireEye suggests at least one attack was conducted by a nation-state against a Russian target; however, FireEye researchers also believe other actors may also be leveraging the vulnerability to conduct attacks.
According to a blog post on Tuesday, the Microsoft .Net Framework flaw has been detected and neutralized. Microsoft strongly recommends installing the latest update promptly to reduce exposure. Microsoft says the flaw could allow a malicious actor to take full control of an affected system.
BlueBorne Bluetooth Bug Fixed
Several Bluetooth vulnerabilities were discovered and disclosed on Tuesday by security firm Aramis. The vulnerabilities affect billions of Bluetooth-enabled devices around the world. The eight vulnerabilities, termed BlueBorne, could be used to perform man-in-the-middle attacks on devices via Bluetooth, rerouting traffic to the attacker’s computer. The bugs exist in Windows, iOS, Android and Linux.
In order to exploit the vulnerabilities, Bluetooth would need to be enabled on the targeted device, although it would not be necessary for the device to be in discoverable mode. An attacker could use the vulnerabilities to connect to a device – a TV or speaker for example – and initiate a connection to a computer without the user’s knowledge. In order to pull off the attack, it would be necessary to be in relatively close proximity to the targeted device.
In addition to intercepting communications, an attacker could also take full control of a device and steal data, download ransomware or malware, or perform other malicious activities such as adding the device to a botnet. Microsoft corrected one of the Bluetooth driver spoofing bugs – CVE-2017-8628 – in the latest round of updates.
Critical NetBIOS Remote Code Execution Vulnerability Patched
One of the most pressing updates is for a remote code execution vulnerability in NetBIOS (CVE-2017-0161). The vulnerability affects both servers and workstations. While the vulnerability is not believed to be currently exploited in the wild, it is of note as it can be exploited simply by sending specially crafted NetBT Session Service packets.
The Zero Day Initiative (ZDI) said the flaw “is practically wormable within a LAN. This could also impact multiple virtual clients if the guest OSes all connect to the same (virtual) LAN.”
In total, 81 updates have been released by Microsoft this Patch Tuesday. Adobe has corrected eight flaws, including two critical memory corruption bugs (CVE-2017-11281, CVE-2017-11282) in Flash Player, a critical XML parsing vulnerability in ColdFusion (CVE-2017-11286) and two ColdFusion remote code execution vulnerabilities (CVE-2017-11283, CVE-2017-11284) concerning deserialization of untrusted data.