CVE Vulnerability

CVE-2020-26278

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.

7.9 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 5.5 / Impact : 10

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact COMPLETE

Integrity Impact COMPLETE

Availability Impact COMPLETE

Scope

8 /10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 1.3 / Impact : 6

Attack Vector ADJACENT_NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

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

Configuration 1

cpe:2.3:a:weave:weave:*:*:*:*:*:*:*:*
Information

Published : 2021-01-20 10:15

Updated : 2021-02-02 03:26

NVD link : CVE-2020-26278

Mitre link : CVE-2020-26278

Products Affected
No products.
CWE
CWE-250

Execution with Unnecessary Privileges