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CVE-2021-47109

7.5 · HIGH

In the Linux kernel, the following vulnerability has been resolved: neighbour: allow NUD_NOARP entries to be forced GCed IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6.

Published Mar 15, 2024CWE-190EPSS 0.69%

Overview

CVE-2021-47109 is a high-severity vulnerability. It was published on March 15, 2024 and has a CVSS 3.1 base score of 7.5 (HIGH).

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical description

In the Linux kernel, the following vulnerability has been resolved:

neighbour: allow NUD_NOARP entries to be forced GCed

IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6. It's possible to

fill up the neighbour table with enough entries that it will overflow for

valid connections after that.

This behaviour is more prevalent after commit 58956317c8de ("neighbor:

Improve garbage collection") is applied, as it prevents removal from

entries that are not NUD_FAILED, unless they are more than 5s old.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refgit.kernel.org/stable/c/7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8fRefgit.kernel.org/stable/c/d17d47da59f726dc4c87caebda3a50333d7e2fd3Refgit.kernel.org/stable/c/d99029e6aab62aef0a0251588b2867e77e83b137Refgit.kernel.org/stable/c/ddf088d7aaaaacfc836104f2e632b29b1d383cfcRefgit.kernel.org/stable/c/7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8fRefgit.kernel.org/stable/c/d17d47da59f726dc4c87caebda3a50333d7e2fd3Refgit.kernel.org/stable/c/d99029e6aab62aef0a0251588b2867e77e83b137Refgit.kernel.org/stable/c/ddf088d7aaaaacfc836104f2e632b29b1d383cfc

How CyberStrike helps

Frequently asked questions

What is CVE-2021-47109?

CVE-2021-47109 is a high-severity vulnerability. It was published on March 15, 2024 and has a CVSS 3.1 base score of 7.5 (HIGH).

How severe is CVE-2021-47109?

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2021-47109?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2021-47109?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2021-47109 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

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