Exploited vulnerability · CISA KEV

Is CVE-2016-7255 exploited? Yes: in CISA KEV since 3 Nov 2021

Gociux · Microsoft Win32k · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2016-7255, Microsoft Win32k Privilege Escalation Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 3 Nov 2021, 1819 days after it was published. It is known to be used in ransomware campaigns. It affects Microsoft Win32k. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

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.

What to do

1. Check whether you run it. Look for Win32k in your asset inventory, including appliances and cloud images. Stack check lists every exploited Microsoft CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 10 Nov 2016.
4. Get told next time. Email alerts when CISA adds a CVE for Microsoft.

Other exploited CVEs in Win32k

• CVE-2016-0165: Microsoft Win32k Privilege Escalation Vulnerability (22 Jun 2023)
• CVE-2023-29336: Microsoft Win32K Privilege Escalation Vulnerability (9 May 2023)
• CVE-2015-2360: Microsoft Win32k Privilege Escalation Vulnerability (25 May 2022)
• CVE-2018-8589: Microsoft Win32k Privilege Escalation Vulnerability (23 May 2022)
• CVE-2014-4113: Microsoft Win32k Privilege Escalation Vulnerability (4 May 2022)
• CVE-2021-41357: Microsoft Win32k Privilege Escalation Vulnerability (25 Apr 2022)

References

• nvd.nist.gov/vuln/detail/CVE-2016-7255

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in November 2021 · Microsoft scorecard · act-now radar.