Integer underflow in Linux kernel - CVE-2021-47222
Published: June 10, 2024 / Updated: May 13, 2025
Vulnerability identifier: #VU91666
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-47222
CWE-ID: CWE-191
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to execute arbitrary code.
The vulnerability exists due to integer underflow within the br_handle_egress_vlan_tunnel() function in net/bridge/br_vlan_tunnel.c. A local user can execute arbitrary code.
How to mitigate CVE-2021-47222
Install update from vendor's website.
Sources
- https://git.kernel.org/stable/c/42020f7f37a90d24b9551f5f7eba3f7c7c102968
- https://git.kernel.org/stable/c/84fc1c944e45ab317e2e70a0e7f76fa2a5e43b6e
- https://git.kernel.org/stable/c/79855be6445b6592bddb7bd7167083ec8cdbd73f
- https://git.kernel.org/stable/c/fc7fdd8c5c2ad2fe3e297698be9d4dbe4a4e0579
- https://git.kernel.org/stable/c/25053a8404ba17ca48f5553d487afc1882e9f56c
- https://git.kernel.org/stable/c/cfc579f9d89af4ada58c69b03bcaa4887840f3b3
- https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.238
- https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.196
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.46
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.13
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.128