Vulnerabilities in MMC allow taking control over the system

The Microsoft Management Console (MMC), used by system administrators to configure and track system performance, contains a number of vulnerabilities, using which attackers can implement malware or intercept control on the attacked machine.

The vulnerability group, which includes XSS and XXE bugs, received a common identifier CVE-2019-0948. Attackers can exploit problems using the snap-in mechanism in the MMC. Snap-ins are small programs that allow customizing different aspects of the system.

In order to exploit the vulnerability, an attacker will need to create a file with the .msc extension, containing specially crafted XML content, and then convince an authorized user (for example, using social engineering) to import this file.

As the researchers from Check Point, who discovered the bugs, explained, an attacker can create a file with the Link to Web Address snap-in (link to a web-resource) and include a link to its own server, thus redirecting to a page with malicious code.

“We have successfully managed to insert malicious URL link that contains malicious payloads such as redirection to SMB server that will capture the user NTLM hash”, — report researchers.

In the same way, an attacker can create a file with the ActiveX Control snap-in and save it as an .msc file by changing the string value in the StringsTables section to a malicious URL controlled by it.

According to experts, MMC files are used by system administrators and are not considered antivirus software as malicious. Cybercriminals can take advantage of it to control of a PC with administrator status and further advance over the network.

The problems affect versions of Windows 7, Windows 8.1, Windows 10 and Windows Server 2008 – Windows Server 2019. Microsoft has already fixed vulnerabilities with the release of June service pack. Currently, there are no cases of bugs’ exploitation.

Source: https://research.checkpoint.com