CVE-2021-47109 - CVE House
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Status published Medium CVE-2021-47109

neighbour: allow NUD_NOARP entries to be forced GCed

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

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Affected Vendor

Affected Software

Linux
Vulnerable Versions:
58956317c8de52009d1a38a721474c24aef74fe7, 5.0, 0, 5.4.125, 5.10.43, 5.12.10, 5.13

Timeline

Official Publish: March 15th, 2024
Last Modified: May 11th, 2026
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.