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Exploited in the wildUsed by ransomwareComputers & everyday appsCould reach you

CVE-2016-7255 Microsoft Win32k: privilege escalation

In plain words: Something running with limited rights can promote itself to full control. Turns a small foothold (like a malicious app) into administrator or system-level access.

Confirmed exploited by CISA on · US federal patch deadline May 3, 2022

What to do

  1. Install Microsoft's security update for Win32k. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Turn on automatic updates for the operating system and for Office, PDF and archive apps.
  3. Be careful with unexpected attachments — documents, .zip/.rar files and shortcuts are common bait.
  4. Use a normal (non-admin) account day to day and keep built-in protection like Microsoft Defender on.

Who is affected

Could reach you. Used in ransomware, which spreads to ordinary people and small businesses.

What's at risk: Your files, saved passwords and accounts. Many of these let a program that is already running gain full administrator control.

The details

Official name
Microsoft Win32k Privilege Escalation Vulnerability
Product
Microsoft Win32k
CISA description
Microsoft Win32k kernel-mode driver fails to properly handle objects in memory which allows for privilege escalation. Successful exploitation allows an attacker to run code in kernel mode.
Type of flaw
Privilege escalation (CWE-264)
Confirmed exploited
Nov 3, 2021 — known to be used in ransomware attacks
US federal patch deadline
May 3, 2022

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Answering about CVE-2016-7255 ·

Questions about CVE-2016-7255

Is CVE-2016-7255 being exploited?

Yes. CISA added CVE-2016-7255 to its Known Exploited Vulnerabilities catalog on Nov 3, 2021, which means there is reliable evidence of real-world attacks, including by ransomware groups.

How do I fix CVE-2016-7255?

Install Microsoft's security update for Win32k. If no update exists, follow the vendor's workaround or stop using the product until one ships. Turn on automatic updates for the operating system and for Office, PDF and archive apps.

Am I affected by CVE-2016-7255?

Only if you use Microsoft Win32k. Used in ransomware, which spreads to ordinary people and small businesses.

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