CVE-2021-47109
kernel: neighbour: allow NUD_NOARP entries to be forced GCed
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 15, 2024
Updated · August 5, 2026
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.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CWE-121 · Stack-based Buffer Overflow