CVE-2019-1367: Critical Internet Explorer Memory Corruption Vulnerability Exploited In The Wild
Zero-day memory corruption vulnerability in Internet Explorer has been observed in attacks in the wild
Background
On September 23, Microsoft released an out-of-band patch for a zero-day vulnerability in Internet Explorer that has been exploited in the wild.
Analysis
CVE-2019-1367 is a memory corruption vulnerability in Internet Explorer’s scripting engine in the way that objects in memory are handled. Exploitation of this vulnerability could result in the attacker gaining arbitrary code execution under the same privileges as the current user. In the event that the current user has administrative privileges, an attacker could perform various actions on the system, from creating a new account with full privileges to installing programs or even modifying data.
To exploit the vulnerability, an attacker would have to host the exploit on a malicious website and socially engineer a user into opening that website in Internet Explorer. In the case of a targeted attack, an attacker could include a link to the malicious website in an email or in a malicious email attachment (HTML file, PDF file, Microsoft Office document) that supports embedding the scripting engine content.
The vulnerability was discovered by Clément Lecigne of Google’s Threat Analysis Group (TAG). Earlier this year, Lecigne discovered and reported two zero-day vulnerabilities: a use-after-free vulnerability in Google Chrome (CVE-2019-5786) and an elevation of privilege vulnerability in Microsoft Windows (CVE-2019-0808) that were exploited together in the wild.
Additional details about the in-the-wild exploitation of this vulnerability have not yet been made public by Lecigne and Google’s TAG, though we anticipate such details will be disclosed in a blog post in the near future.
Proof of concept
At the time this blog was published, no proof-of-concept (PoC) was available.
Solution
Microsoft released an out-of-band patch for this vulnerability due to the report that it has been exploited in the wild. Please refer to the Security Updates section for additional information on the IE Cumulative Update or relevant Security Updates.
Additionally, Microsoft has provided workarounds for both 32-bit and 64-bit systems by restricting access to the JScript.dll file. An administrator can do so by entering specific commands into the command prompt; the commands are available at the end of the security advisory page. However, these workarounds should only be used as a temporary measure until patching is feasible. Commands to revert the workarounds are also available on the Microsoft security advisory page linked above.
Identifying affected systems
A list of Tenable plugins to identify this vulnerability will appear here as they’re released.
Get more information
Join Tenable's Security Response Team on the Tenable Community.
Learn more about Tenable, the first Cyber Exposure platform for holistic management of your modern attack surface.
Get a free 60-day trial of Tenable.io Vulnerability Management.
Related Articles
Volt Typhoon: What State and Local Government Officials Need to Know
November 19, 2024Increased activity from the state-sponsored threat group Volt Typhoon raises concerns about the cybersecurity of U.S. critical infrastructure. Here’s how you can identify potential exposures and attack paths.
Cybersecurity Snapshot: Guide Unpacks Event-Logging Best Practices, as FAA Proposes Stronger Cyber Rules for Airplanes
August 23, 2024Looking to sharpen your team’s event logging and threat detection? A new guide offers plenty of best practices. Plus, the FAA wants airplanes to be more resilient to cyberattacks. Meanwhile, check out the critical vulnerabilities Tenable discovered in two Microsoft AI products. And get the latest on ransomware trends, vulnerability management practices and election security!
Detecting Risky Third-party Drivers on Windows Assets
August 7, 2024Kernel-mode drivers are critical yet risky components of the Windows operating system. Learn about their functionality, the dangers they pose, and how Tenable's new plugins can help identify and mitigate vulnerabilities using community-driven resources like LOLDrivers.
Cybersecurity Snapshot: Prompt Injection and Data Disclosure Top OWASP’s List of Cyber Risks for GenAI LLM Apps
November 22, 2024Don’t miss OWASP’s update to its “Top 10 Risks for LLMs” list. Plus, the ranking of the most harmful software weaknesses is out. Meanwhile, critical infrastructure orgs have a new framework for using AI securely. And get the latest on the BianLian ransomware gang and on the challenges of protecting water and transportation systems against cyberattacks.
Active Directory Under Attack: Five Eyes Guidance Targets Crucial Security Gaps
November 21, 2024A landmark global report from cybersecurity agencies emphasizes 17 attack techniques against Microsoft Active Directory and cautions organizations to step up protections. In the first of our two-part series, we offer five steps you can take today to shore up your AD defenses.
Five Cyber Agencies Sound Alarm About Active Directory Attacks: Beyond the Basics
November 21, 2024A landmark global report emphasizes 17 attack techniques against Microsoft Active Directory and cautions organizations to step up protections. In the second of our two-part series, we take you beyond the basics to highlight three key areas to focus on.
- Threat Intelligence
- Threat Management
- Vulnerability Management
- Vulnerability Scanning