CVE-2020-12114
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Description
A flaw was found in the Linux kernel’s implementation of the pivot_root syscall. This flaw allows a local privileged user (root outside or root inside a privileged container) to exploit a race condition to manipulate the reference count of the root filesystem. To be able to abuse this flaw, the process or user calling pivot_root must have advanced permissions. The highest threat from this vulnerability is to system availability.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Additional information
- Bugzilla 1848652: kernel: DoS by corrupting mountpoint reference counter
- CWE-400: Uncontrolled Resource Consumption
- FAQ: Frequently asked questions about CVE-2020-12114
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
| Red Hat | NVD | |
|---|---|---|
CVSS v3 Base Score | 4.4 | 4.7 |
Attack Vector | Local | Local |
Attack Complexity | Low | High |
Privileges Required | High | Low |
User Interaction | None | None |
Scope | Unchanged | Unchanged |
Confidentiality Impact | None | None |
Integrity Impact | None | None |
Availability Impact | High | High |
CVSS v3 Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat CVSS v3 Score Explanation
A local privileged user (root outside or root inside a privileged container, AC:H) could exploit a race condition to manipulate the reference count of the root filesystem. To be able to abuse this flaw, the process or user calling pivot_root must have advanced permissions. Then the attack complexity is low (AC:L).
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
The most common result of resource exhaustion is denial of service. The product may slow down, crash due to unhandled errors, or lock out legitimate users.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
What can I do if my product is listed as "Will not fix"?
What can I do if my product is listed as "Fix deferred"?
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
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