Microsoft Windows Privilege Escalation
CVE-2019-0543 is a high-severity improper authentication vulnerability in Windows 10 1507 from Microsoft, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on March 15, 2022, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Windows 10 1507 you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on portal.msrc.microsoft.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Windows 10 1507 | Not specified in the record | Not stated |
| Microsoft | Windows 10 1607 | Not specified in the record | Not stated |
| Microsoft | Windows 10 1703 | Not specified in the record | Not stated |
| Microsoft | Windows 10 1709 | Not specified in the record | Not stated |
| Microsoft | Windows 10 1803 | Not specified in the record | Not stated |
| Microsoft | Windows 10 1809 | Not specified in the record | Not stated |
| Microsoft | Windows 7 | Not specified in the record | Not stated |
| Microsoft | Windows 8.1 | Not specified in the record | Not stated |
| Microsoft | Windows Rt 8.1 | Not specified in the record | Not stated |
| Microsoft | Windows Server 1709 | Not specified in the record | Not stated |
| Microsoft | Windows Server 1803 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2008 | r2 | Not stated |
| Microsoft | Windows Server 2012 | r2 | Not stated |
| Microsoft | Windows Server 2016 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2019 | Not specified in the record | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
| CVSS 2.0 | 4.6 | Medium | NVD |
Official description
An elevation of privilege vulnerability exists when Windows improperly handles authentication requests, aka "Microsoft Windows Elevation of Privilege Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2019, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-0543US Government Resource
Technical write-ups (may include proof of concept)
- exploit-db.com/exploits/46156/Exploit, Third Party Advisory, VDB Entry
Other vulnerabilities in Windows 10 1507
- 7.0 High severity
- 7.8 High severity
- 7.0 High severity
- 7.7 High severity
- 7.0 High severity
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