#VU90464 NULL pointer dereference in Linux kernel - CVE-2021-47223
Vulnerability identifier: #VU90464
Vulnerability risk: Low
CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2021-47223
CWE-ID:
CWE-476
Exploitation vector: Local
Exploit availability: No
Vulnerable software:
Linux kernel
Operating systems & Components /
Operating system
Vendor: Linux Foundation
Description
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to NULL pointer dereference within the br_vlan_tunnel_lookup(), __vlan_tunnel_info_add(), br_handle_ingress_vlan_tunnel() and br_handle_egress_vlan_tunnel() functions in net/bridge/br_vlan_tunnel.c. A local user can perform a denial of service (DoS) attack.
Mitigation
Install update from vendor's website.
Vulnerable software versions
Linux kernel: 4.14, 4.14.0, 4.14.0 rc1, 4.14.1, 4.14.2, 4.14.3, 4.14.4, 4.14.5, 4.14.6, 4.14.7, 4.14.8, 4.14.9, 4.14.10, 4.14.11, 4.14.12, 4.14.13, 4.14.14, 4.14.15, 4.14.16, 4.14.17, 4.14.18, 4.14.19, 4.14.20, 4.14.21, 4.14.22, 4.14.23, 4.14.24, 4.14.25, 4.14.26, 4.14.27, 4.14.28, 4.14.29, 4.14.30, 4.14.31, 4.14.32, 4.14.33, 4.14.34, 4.14.35, 4.14.36, 4.14.37, 4.14.38, 4.14.39, 4.14.40, 4.14.41, 4.14.42, 4.14.43, 4.14.44, 4.14.45, 4.14.46, 4.14.47, 4.14.48, 4.14.49, 4.14.50, 4.14.51, 4.14.52, 4.14.53, 4.14.54, 4.14.55, 4.14.56, 4.14.57, 4.14.58, 4.14.59, 4.14.60, 4.14.61, 4.14.62, 4.14.63, 4.14.64, 4.14.65, 4.14.66, 4.14.67, 4.14.68, 4.14.69, 4.14.70, 4.14.71, 4.14.72, 4.14.73, 4.14.74, 4.14.75, 4.14.76, 4.14.77, 4.14.78, 4.14.79, 4.14.80, 4.14.81, 4.14.82, 4.14.83, 4.14.84, 4.14.85, 4.14.86, 4.14.87, 4.14.88, 4.14.89, 4.14.90, 4.14.91, 4.14.92, 4.14.93, 4.14.94, 4.14.95, 4.14.96, 4.14.97, 4.14.98, 4.14.99, 4.14.100, 4.14.101, 4.14.102, 4.14.103, 4.14.104, 4.14.105, 4.14.106, 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External links
https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79
https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530
https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c
https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7
https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d
https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f
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
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
