CVE-2020-26278 Detail

Current Description

Weave Net is open source software which creates a virtual network that connects Docker containers across multiple hosts and enables their automatic discovery. Weave Net before version 2.8.0 has a vulnerability in which can allow an attacker to take over any host in the cluster. Weave Net is supplied with a manifest that runs pods on every node in a Kubernetes cluster, which are responsible for managing network connections for all other pods in the cluster. This requires a lot of power over the host, and the manifest sets `privileged: true`, which gives it that power. It also set `hostPID: true`, which gave it the ability to access all other processes on the host, and write anywhere in the root filesystem of the host. This setting was not necessary, and is being removed. You are only vulnerable if you have an additional vulnerability (e.g. a bug in Kubernetes) or misconfiguration that allows an attacker to run code inside the Weave Net pod, No such bug is known at the time of release, and there are no known instances of this being exploited. Weave Net 2.8.0 removes the hostPID setting and moves CNI plugin install to an init container. Users who do not update to 2.8.0 can edit the hostPID line in their existing DaemonSet manifest to say false instead of true, arrange some other way to install CNI plugins (e.g. Ansible) and remove those mounts from the DaemonSet manifest.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  8.0 HIGH
Vector:  CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
Base Score:  5.8 MEDIUM
Vector:  CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:N


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/weaveworks/weave/blob/master/CHANGELOG.md#release-280 Release Notes  Third Party Advisory 
https://github.com/weaveworks/weave/commit/a0ac81b3b4cae6d0dcaf3732fd91cedefc89f720 Patch  Third Party Advisory 
https://github.com/weaveworks/weave/pull/3876 Patch  Third Party Advisory 
https://github.com/weaveworks/weave/security/advisories/GHSA-pg3p-v8c6-c6h3 Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-250 Execution with Unnecessary Privileges Provider acceptance level GitHub, Inc.  

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2020-26278
NVD Published Date:
01/20/2021
NVD Last Modified:
02/02/2021
Source:
GitHub, Inc.