Vulnerability Details : CVE-2021-40449
Win32k Elevation of Privilege Vulnerability
Vulnerability category: Gain privilege
At least one public exploit which can be used to exploit this vulnerability exists!
CVE-2021-40449
is in the CISA Known Exploited Vulnerabilities Catalog
CISA vulnerability name:
Microsoft Windows Win32k Privilege Escalation Vulnerability
CISA required action:
Apply updates per vendor instructions.
CISA description:
Unspecified vulnerability allows for an authenticated user to escalate privileges.
Added on
2021-11-17
Action due date
2021-12-01
Exploit prediction scoring system (EPSS) score for CVE-2021-40449
Probability of exploitation activity in the next 30 days: 0.15%
Percentile, the proportion of vulnerabilities that are scored at or less: ~ 51 % EPSS Score History EPSS FAQ
Metasploit modules for CVE-2021-40449
-
Win32k NtGdiResetDC Use After Free Local Privilege Elevation
Disclosure Date : 2021-10-12exploit/windows/local/cve_2021_40449A use after free vulnerability exists in the `NtGdiResetDC()` function of Win32k which can be leveraged by an attacker to escalate privileges to those of `NT AUTHORITY\SYSTEM`. The flaw exists due to the fact that this function calls `hdcOpenDCW()`, which performs a user mode callback. During this callback, attackers can call the `NtGdiResetDC()` function again with the same handle as before, which will result in the PDC object that is referenced by this handle being freed. The attacker can then replace the memory referenced by the handle with their own object, before passing execution back to the original `NtGdiResetDC()` call, which will now use the attacker's object without appropriate validation. This can then allow the attacker to manipulate the state of the kernel and, together with additional exploitation techniques, gain code execution as NT AUTHORITY\SYSTEM. This modul
CVSS scores for CVE-2021-40449
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Source |
---|---|---|---|---|---|
4.6
|
MEDIUM | AV:L/AC:L/Au:N/C:P/I:P/A:P |
3.9
|
6.4
|
[email protected] |
7.8
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.8
|
5.9
|
[email protected] |
7.8
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.8
|
5.9
|
[email protected] |
CWE ids for CVE-2021-40449
-
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.Assigned by: [email protected] (Primary)
References for CVE-2021-40449
-
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40449
Patch;Vendor Advisory
-
http://packetstormsecurity.com/files/164926/Win32k-NtGdiResetDC-Use-After-Free-Local-Privilege-Escalation.html
Exploit;Third Party Advisory;VDB Entry
Products affected by CVE-2021-40449
- cpe:2.3:o:microsoft:windows_server:20h2:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
- cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_10:21h1:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:*
- cpe:2.3:o:microsoft:windows_11:*:*:*:*:*:*:*:*