CVE-2020-0636: Windows Subsystem for Linux Elevation of Privilege Vulnerability
CVE-2020-0636 is an elevation of privilege vulnerability in Windows Subsystem for Linux, rated Important by Microsoft, with a CVSS 3.0 base score of 7.8 (High). 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 0.82% probability of exploitation activity in the next 30 days, higher than 57% of all scored vulnerabilities. Microsoft released the fix on 14 January 2020 in the January 2020 Patch Tuesday, delivered through 1 security update (KB4528760). It affects 8 products in 1 product family (Windows).
Key facts
- CVE ID
- CVE-2020-0636
- Severity
- High CVSS 7.8
- Microsoft severity
- Important
- Impact
- Elevation of Privilege
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- EPSS
- 0.82% (percentile 57%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- January 2020 Patch Tuesday
- Product families
- Windows
CVSS score and vector
Microsoft scores CVE-2020-0636 at 7.8 (temporal 7) using CVSS 3.0. Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Proof of concept |
| Remediation level | Official fix |
| Report confidence | Confirmed |
NVD scores it 7.8 (HIGH) with CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Description
An elevation of privilege vulnerability exists in the way that the Windows Subsystem for Linux handles files. An attacker who successfully exploited the vulnerability could execute code with elevated privileges.
To exploit the vulnerability, an attacker would first need code execution on a victim system. An attacker could then run a specially crafted application.
The security update addresses the vulnerability by correcting how the Windows Subsystem for Linux handles files.
Affected products (8)
Windows
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Windows 10 Version 1903 for 32-bit Systems | KB4528760 | Security Update | Yes | |
| Windows 10 Version 1903 for x64-based Systems | ||||
| Windows 10 Version 1903 for ARM64-based Systems | ||||
| Windows Server, version 1903 (Server Core installation) | ||||
| Windows 10 Version 1909 for 32-bit Systems | ||||
| Windows 10 Version 1909 for x64-based Systems | ||||
| Windows 10 Version 1909 for ARM64-based Systems | ||||
| Windows Server, version 1909 (Server Core installation) |
Security updates (1)
- KB4528760 (Security Update)
NIST NVD data
- NVD status
- Modified
- NVD CVSS
- 7.8 (HIGH)
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| windows 10 1903 | all listed versions |
| windows 10 1909 | all listed versions |
| windows server 2016 1903 | all listed versions |
| windows server 2016 1909 | all listed versions |
References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0636 (Patch, Vendor Advisory)
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0636 (Patch, Vendor Advisory)
Acknowledgments
- Andrea Pierini & Christian Danieli
- Jarvis_1oop of Pinduoduo Security Research Lab
- Zhiniang Peng (@edwardzpeng) of Qihoo 360 Core Security and Jiadong Lu
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. | |
| 1.1 | Added an acknowledgement. |