Google this week released information on a zero-day vulnerability in Windows being actively exploited in targeted attacks alongside a recently fixed Chrome flaw (CVE-2019-5786).
The Windows vulnerability has been described as a local privilege escalation in the win32k.sys kernel driver and it can be abused for a security sandbox escape.
“The vulnerability is a NULL pointer dereference in win32k!MNGetpItemFromIndex when NtUserMNDragOver() system call is called under specific circumstances,” Clement Lecigne of Google’s Threat Analysis Group explains.
The bug is believed to be exploitable only on Windows 7 systems, due to exploit mitigations Microsoft has added in newer versions of Windows. In fact, the observed exploitation of the flaw only targeted Windows 7 32-bit systems so far.
The security bug was reported to Microsoft last week, and Google decided to make the information public although a patch isn’t available yet.
According to Lecigne, they decided to publicly disclose the vulnerability due to the fact that it’s serious and is being actively exploited in targeted attacks.
“The unpatched Windows vulnerability can still be used to elevate privileges or combined with another browser vulnerability to evade security sandboxes. Microsoft have told us they are working on a fix,” Lecigne notes.
To mitigate the vulnerability, users should consider upgrading to Windows 10. They are also encouraged to apply patches as soon as they become available.
The Chrome vulnerability exploited in the same attacks is CVE-2019-5786, which Google discovered last month and quickly addressed on March 1. The company revealed on March 5 that this flaw had been exploited in live attacks when the patch was released.
Google pushed the update (version 72.0.3626.121) through Chrome auto-update, but Lecigne now encourages users to check whether the update has been downloaded and applied or not.
The reason for this, Director of Chrome Security and Desktop Justin Schuh explains, is that the exploit for this browser vulnerability is different from those targeting previously observed zero-days in Chrome, which relied on Flash as the first exploit in the chain.
“This newest exploit is different, in that initial chain targeted Chrome code directly, and thus required the user to have restarted the browser after the update was downloaded. For most users the update download is automatic, but restart is usually a manual action,” Schuh reveals.
Related: Google Patches Actively Exploited Chrome Vulnerability
Related: Google Finds Internet Explorer Zero-Day Exploited in Targeted Attacks

More from Ionut Arghire
- Generative AI Startup Nexusflow Raises $10.6 Million
- Researchers Extract Sounds From Still Images on Smartphone Cameras
- Hackers Set Sights on Apache NiFi Flaw That Exposes Many Organizations to Attacks
- Cloudflare Users Exposed to Attacks Launched From Within Cloudflare: Researchers
- FBI Warns Organizations of Dual Ransomware, Wiper Attacks
- Lumu Raises $30 Million for Threat Detection and Response Platform
- Cisco Warns of IOS Software Zero-Day Exploitation Attempts
- Russian Zero-Day Acquisition Firm Offers $20 Million for Android, iOS Exploits
Latest News
- Bankrupt IronNet Shuts Down Operations
- AWS Using MadPot Decoy System to Disrupt APTs, Botnets
- Generative AI Startup Nexusflow Raises $10.6 Million
- In Other News: RSA Encryption Attack, Meta AI Privacy, ShinyHunters Hacker Guilty Plea
- Researchers Extract Sounds From Still Images on Smartphone Cameras
- National Security Agency is Starting an Artificial Intelligence Security Center
- CISA Warns of Old JBoss RichFaces Vulnerability Being Exploited in Attacks
- Hackers Set Sights on Apache NiFi Flaw That Exposes Many Organizations to Attacks
