Windows 10 Version 20H2: NULL Pointer Dereference
CVE-2022-32230 is a high-severity NULL pointer dereference vulnerability in Windows 10 Version 20H2 from Microsoft, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 19042.1706, 19043.1706 as the first without the flaw, so updating Windows 10 Version 20H2 to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 7.93% chance of exploitation within 30 days, which is in the top 5.18% of all scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Windows 10 Version 20H2 to 19042.1706 or 19043.1706, whichever matches your release line, or a later version.
- Update Windows Server Version 20H2 to 19042.1706 or 19043.1706 or 19044.1706, whichever matches your release line, or a later version.
- Update Windows 10 Version 21H1 to 19042.1706 or 19043.1706 or 19044.1706, whichever matches your release line, or a later version.
- Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Windows 10 Version 20H2 | 19042.1706 up to, but not including, 19042.1706; 19043.1706 up to, but not including, 19043.1706; 19044.1706 up to, but not including, 19043.1706 | 19042.1706, 19043.1706 |
| Microsoft | Windows Server Version 20H2 | 19042.1706 up to, but not including, 19042.1706; 19043.1706 up to, but not including, 19043.1706; 19044.1706 up to, but not including, 19044.1706 | 19042.1706, 19043.1706, 19044.1706 |
| Microsoft | Windows 10 Version 21H1 | 19042.1706 up to, but not including, 19042.1706; 19043.1706 up to, but not including, 19043.1706; 19044.1706 up to, but not including, 19044.1706 | 19042.1706, 19043.1706, 19044.1706 |
| Microsoft | Windows 10 Version 21H2 | 19042.1706 up to, but not including, 19042.1706; 19043.1706 up to, but not including, 19043.1706; 19044.1706 up to, but not including, 19044.1706 | 19042.1706, 19043.1706, 19044.1706 |
| Microsoft | Windows 10 | 20h2; 21h1; 21h2; 1809 | Not stated |
| Microsoft | Windows 11 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2019 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (rapid7.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 7.8 | High | NVD |
Official description
Microsoft Windows SMBv3 suffers from a null pointer dereference in versions of Windows prior to the April, 2022 patch set. By sending a malformed FileNormalizedNameInformation SMBv3 request over a named pipe, an attacker can cause a Blue Screen of Death (BSOD) crash of the Windows kernel. For most systems, this attack requires authentication, except in the special case of Windows Domain Controllers, where unauthenticated users can always open named pipes as long as they can establish an SMB session. Typically, after the BSOD, the victim SMBv3 server will reboot.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Technical write-ups (may include proof of concept)
- github.com/zeroSteiner/metasploit-framework/blob/feat/mod/cve-2022-32230/modules/auxiliary/dos/smb/smb_fileno…Exploit, Third Party Advisory
- rapid7.com/blog/post/2022/06/14/cve-2022-32230-windows-smb-denial-of-service-vulnerability-fixed/Exploit, Third Party Advisory
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Spotted an error? Tell us.