5.8
MEDIUM
CVE-2020-11091
Weave Net IPv6 Router Advertisement Hijacking Vulnerability
Description

In Weave Net before version 2.6.3, an attacker able to run a process as root in a container is able to respond to DNS requests from the host and thereby insert themselves as a fake service. In a cluster with an IPv4 internal network, if IPv6 is not totally disabled on the host (via ipv6.disable=1 on the kernel cmdline), it will be either unconfigured or configured on some interfaces, but it's pretty likely that ipv6 forwarding is disabled, ie /proc/sys/net/ipv6/conf//forwarding == 0. Also by default, /proc/sys/net/ipv6/conf//accept_ra == 1. The combination of these 2 sysctls means that the host accepts router advertisements and configure the IPv6 stack using them. By sending rogue router advertisements, an attacker can reconfigure the host to redirect part or all of the IPv6 traffic of the host to the attacker controlled container. Even if there was no IPv6 traffic before, if the DNS returns A (IPv4) and AAAA (IPv6) records, many HTTP libraries will try to connect via IPv6 first then fallback to IPv4, giving an opportunity to the attacker to respond. If by chance you also have on the host a vulnerability like last year's RCE in apt (CVE-2019-3462), you can now escalate to the host. Weave Net version 2.6.3 disables the accept_ra option on the veth devices that it creates.

INFO

Published Date :

June 3, 2020, 11:15 p.m.

Last Modified :

June 9, 2020, 8:02 p.m.

Remotely Exploitable :

Yes !

Impact Score :

4.0

Exploitability Score :

1.3
Affected Products

The following products are affected by CVE-2020-11091 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Weave weave_net
2 Weave weave
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2020-11091.

URL Resource
https://github.com/weaveworks/weave/commit/15f21f1899060f7716c70a8555a084e836f39a60 Patch Third Party Advisory
https://github.com/weaveworks/weave/security/advisories/GHSA-59qg-grp7-5r73 Third Party Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2020-11091 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2020-11091 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Initial Analysis by [email protected]

    Jun. 09, 2020

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:M/Au:S/C:N/I:P/A:N)
    Added CVSS V3.1 NIST AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
    Changed Reference Type https://github.com/weaveworks/weave/commit/15f21f1899060f7716c70a8555a084e836f39a60 No Types Assigned https://github.com/weaveworks/weave/commit/15f21f1899060f7716c70a8555a084e836f39a60 Patch, Third Party Advisory
    Changed Reference Type https://github.com/weaveworks/weave/security/advisories/GHSA-59qg-grp7-5r73 No Types Assigned https://github.com/weaveworks/weave/security/advisories/GHSA-59qg-grp7-5r73 Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:a:weave:weave_net:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.3
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2020-11091 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2020-11091 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.05 }} 0.00%

score

0.17086

percentile

CVSS31 - Vulnerability Scoring System
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