Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

4/15/2019
04:00 PM
Connect Directly
Twitter
LinkedIn
Google+
RSS
E-Mail
50%
50%

New Details Emerge on Windows Zero Day

The CVE-2019-0859 vulnerability, patched last week, is the latest in a string of Windows local privilege escalation bugs discovered at Kaspersky Lab.

Kaspersky Lab researchers today disclosed more details about CVE-2019-0859, one of two Windows zero-day vulnerabilities under active attack when Microsoft issued patches early last week.

CVE-2019-0859 and CVE-2019-0803 are elevation of privilege bugs. The former was discovered by Kaspersky Lab researchers Vasiliy Berdnikov and Boris Larin, the latter by Alibaba's Cloud Intelligence Security Team. Berdnikov and Larin teamed up with malware analyst Anton Ivanov to publish more insight around the flaw, which has been reportedly exploited by an "unknown criminal group" trying to gain full control on a target device.

Kaspersky Lab found CVE-2019-0859 last month when their automatic exploit prevention systems detected an attempt to abuse a Windows vulnerability. Further analysis revealed a zero-day bug in win32k.sys – the fifth exploited local privilege escalation vulnerability in Windows they had discovered since October. They reported the bug to Microsoft on March 17; it was patched along with 73 other vulnerabilities on the most recent Patch Tuesday.

The exploit Berdnikov and Larin saw in the wild targeted 64-bit versions of Window, ranging from Windows 7 to 10. This particular attack was directed at the kernel of target systems via a backdoor constructed from a core component of the Windows operating system.

Following successful exploitation, it executed PowerShell with a Base64 encoded command. This command downloaded a second-stage script from PasteBin, and the second-stage PowerShell script executed the third stage – also a PowerShell script. This final script unpacks shellcode, allocates executable memory, copies shellcode to allocated memory, and calls CreateThread to execute shellcode, researchers explain in a blog post. Its primary goal was to create a backdoor, which provided the attacker with persistent access on the target system.

As Microsoft put in its advisory, CVE-2019-0859 would let a successful attacker run malicious code in kernel mode and install programs, view, change, or delete data, or create new accounts with full user rights. They'd have to first log onto the system and run the crafted application.

"This allows you to escalate privilege and get the same privileges the system has," Larin says. "It's the highest level of privilege you can have."

What makes this incident particularly interesting is the attacker used the Metasploit framework, a publicly available tool, in conjunction with an exploit that's much harder for attackers to come by. "Zero-day exploits [are] not available for the general public," Larin continues. "Only advanced actors use them." The use of Metasploit also complicates attribution in this scenario, Larin explains, because it's freely available for everyone.

Taking a look back, this string of privilege escalation bug discoveries started with CVE-2018-8453, which was found by the Kaspersky Lab team in August and fixed in October. The exploit was seen being used in targeted attacks, during which it was executed by the first stage of a malware installer to achieve privileges needed to persist on victim systems. In November, Microsoft patched CVE-2018-8589, another Windows zero-day found by the KL researchers.

The trend continued: December brought a patch for CVE-2018-8611, a Win32k elevation of privilege flaw inside the Kernel Transaction Manager that could be used to escape the sandbox in modern browsers. In March, Microsoft patched CVE-2019-0797, a Windows zero-day believed to be in use among several attack groups, including FruityArmor and SandCat.

Cybercriminals are quickly ramping up their use of PowerShell malware, which grew 432% in 2017. This type of malware abuses the legitimate functionality of the scripting tool to launch malicious activity; it's a popular target because it simplifies the concealment of illicit activity.

Related Content:

 

 

 

Join Dark Reading LIVE for two cybersecurity summits at Interop 2019. Learn from the industry's most knowledgeable IT security experts. Check out the Interop agenda here.

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Stop Defending Everything
Kevin Kurzawa, Senior Information Security Auditor,  2/12/2020
Small Business Security: 5 Tips on How and Where to Start
Mike Puglia, Chief Strategy Officer at Kaseya,  2/13/2020
5 Common Errors That Allow Attackers to Go Undetected
Matt Middleton-Leal, General Manager and Chief Security Strategist, Netwrix,  2/12/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
6 Emerging Cyber Threats That Enterprises Face in 2020
This Tech Digest gives an in-depth look at six emerging cyber threats that enterprises could face in 2020. Download your copy today!
Flash Poll
How Enterprises Are Developing and Maintaining Secure Applications
How Enterprises Are Developing and Maintaining Secure Applications
The concept of application security is well known, but application security testing and remediation processes remain unbalanced. Most organizations are confident in their approach to AppSec, although others seem to have no approach at all. Read this report to find out more.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-20477
PUBLISHED: 2020-02-19
PyYAML 5.1 through 5.1.2 has insufficient restrictions on the load and load_all functions because of a class deserialization issue, e.g., Popen is a class in the subprocess module. NOTE: this issue exists because of an incomplete fix for CVE-2017-18342.
CVE-2019-20478
PUBLISHED: 2020-02-19
In ruamel.yaml through 0.16.7, the load method allows remote code execution if the application calls this method with an untrusted argument. In other words, this issue affects developers who are unaware of the need to use methods such as safe_load in these use cases.
CVE-2011-2054
PUBLISHED: 2020-02-19
A vulnerability in the Cisco ASA that could allow a remote attacker to successfully authenticate using the Cisco AnyConnect VPN client if the Secondary Authentication type is LDAP and the password is left blank, providing the primary credentials are correct. The vulnerabilities is due to improper in...
CVE-2015-0749
PUBLISHED: 2020-02-19
A vulnerability in Cisco Unified Communications Manager could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack on the affected software. The vulnerabilities is due to improper input validation of certain parameters passed to the affected software. An attacker ...
CVE-2015-9543
PUBLISHED: 2020-02-19
An issue was discovered in OpenStack Nova before 18.2.4, 19.x before 19.1.0, and 20.x before 20.1.0. It can leak consoleauth tokens into log files. An attacker with read access to the service's logs may obtain tokens used for console access. All Nova setups using novncproxy are affected. This is rel...