PT-2024-11161 · Linux+2 · Linux Kernel+2

Kasper Dupont · Published 2021-06-07 · Updated 2025-02-27 · CVE-2021-47109

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue allows an attacker 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. IFF POINTOPOINT interfaces use NUD NOARP entries for IPv6.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Integer Overflow

Stack Overflow

Weakness Enumeration

CWE-190

CWE-121

Related Identifiers

BDU:2025-04393

CVE-2021-47109

OPENSUSE-SU-2024_1489-1

SUSE-SU-2024:1454-1

SUSE-SU-2024:1465-1

SUSE-SU-2024:1489-1

Affected Products

Astra Linux

Linux Kernel

Suse

References · 350

• https://git.kernel.org/stable/c/ddf088d7aaaaacfc836104f2e632b29b1d383cfc · Patch
• https://ubuntu.com/security/CVE-2021-47109 · Vendor Advisory
• https://git.kernel.org/stable/c/d17d47da59f726dc4c87caebda3a50333d7e2fd3 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-47109 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2024:1454-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2024:1489-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-47109 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2021-47109 · Vendor Advisory
• https://git.kernel.org/stable/c/7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8f · Patch
• https://git.kernel.org/stable/c/d99029e6aab62aef0a0251588b2867e77e83b137 · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-47109 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-04393 · Security Note
• https://osv.dev/vulnerability/CVE-2021-47109 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2024:1465-1 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-47109 · Security Note