CVE-2020-8569
Description
A flaw was found in the Kubernetes snapshot-controller, where it is vulnerable to a denial of service attack via authorized API requests. The snapshot-controller can dereference a NULL pointer when processing a VolumeSnapshot custom resource via an authorized API request with invalid references to PersistentVolumeClaims and VolumeSnapshotClasses. The result causes the snapshot-controller to enter an endless crash loop. The highest threat from this vulnerability is to system availability.
Statement
This vulnerability only affects versions v3.0.0 - v3.0.1 of the upstream snapshot-controller. No released component of OpenShift Container Platform (OCP) includes a vulnerable version. The first release of OCP 4.6 included v3 of a snapshot-controller with this fix, earlier versions of OCP include v2, which is not affected by this vulnerability. Similarly, no components of OpenShift Virtualization include a vulnerable version.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert: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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | 6.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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