CVE-2021-28441: Windows Hyper-V Information Disclosure Vulnerability
CVE-2021-28441 is an information disclosure vulnerability in Windows Hyper-V, rated Important by Microsoft, with a CVSS 3.0 base score of 6.5 (Medium). An attacker can exploit it by an attacker with local access, with low privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. The EPSS model estimates a 0.76% probability of exploitation activity in the next 30 days, higher than 55% of all scored vulnerabilities. Microsoft released the fix on 13 April 2021 in the April 2021 Patch Tuesday, delivered through 3 security updates (KB5001342, KB5001337, KB5001330). It affects 9 products in 1 product family (Windows).
Key facts
- CVE ID
- CVE-2021-28441
- Severity
- Medium CVSS 6.5
- Microsoft severity
- Important
- Impact
- Information Disclosure
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- EPSS
- 0.76% (percentile 55%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- April 2021 Patch Tuesday
- Product families
- Windows
CVSS score and vector
Microsoft scores CVE-2021-28441 at 6.5 (temporal 5.7) using CVSS 3.0. Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Changed |
| Confidentiality impact | High |
| Integrity impact | None |
| Availability impact | None |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
NVD scores it 6.5 (MEDIUM) with CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.
Frequently asked questions (Microsoft)
What type of information could be disclosed by this vulnerability?
The type of information that could be disclosed if an attacker successfully exploited this vulnerability is Guest VM to Hyper-V host server - virtualization security boundary.
Affected products (9)
Windows
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Windows 10 Version 1809 for x64-based Systems | KB5001342 | Security Update | Yes | |
| Windows Server 2019 | KB5001342 | Security Update | Yes | |
| Windows Server 2019 (Server Core installation) | KB5001342 | Security Update | Yes | |
| Windows 10 Version 1909 for x64-based Systems | KB5001337 | Security Update | Yes | |
| Windows Server, version 1909 (Server Core installation) | KB5001337 | Security Update | Yes | |
| Windows 10 Version 2004 for x64-based Systems | KB5001330 | Security Update | Yes | |
| Windows Server, version 2004 (Server Core installation) | KB5001330 | Security Update | Yes | |
| Windows 10 Version 20H2 for x64-based Systems | KB5001330 | Security Update | Yes | |
| Windows Server, version 20H2 (Server Core Installation) | KB5001330 | Security Update | Yes |
Security updates (3)
NIST NVD data
- NVD status
- Modified
- NVD CVSS
- 6.5 (MEDIUM)
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| windows 10 20h2 | all listed versions |
| windows 10 1809 | all listed versions |
| windows 10 1909 | all listed versions |
| windows 10 2004 | all listed versions |
| windows server 2016 20h2 | all listed versions |
| windows server 2016 1909 | all listed versions |
| windows server 2016 2004 | all listed versions |
| windows server 2019 | all listed versions |
References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28441 (Patch, Vendor Advisory)
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28441 (Patch, Vendor Advisory)
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |