CVE-2020-11091Network attack vector

Host traffic interception via rogue router advertisements

Published Jun 3, 2020 · Updated Aug 4, 2024

IPv6 route manipulation in Weave Net before 2.6.3 allows attackers with root in a container to redirect host traffic. Weave-created veth interfaces retain Linux's accept_ra setting, so a container can send router advertisements that the host accepts and uses to rewrite IPv6 routes. Exploitation requires root in a container, CAP_NET_RAW, IPv6 not fully disabled, forwarding off, and router-advertisement acceptance; success places the container in the host's traffic path for impersonation or modification.

CVSS severity5.8
Medium
EPSS probability0.86%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

IPv6 route manipulation in Weave Net before 2.6.3 allows attackers with root in a container to redirect host traffic. Weave-created veth interfaces retain Linux's accept_ra setting, so a container can send router advertisements that the host accepts and uses to rewrite IPv6 routes. Exploitation requires root in a container, CAP_NET_RAW, IPv6 not fully disabled, forwarding off, and router-advertisement acceptance; success places the container in the host's traffic path for impersonation or modification.

The record

CVE
CVE-2020-11091
Published
Jun 3, 2020
Updated
Aug 4, 2024
Vendor
Weaveworks
Product
Weave Net
Classifications
CWE-350, T1557
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 3, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.6.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Weaveworks · Weave Netversion=< 2.6.3

Published CVSS scores

5.8GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-350Reliance on Reverse DNS Resolution for a Security-Critical Action
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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