CVE-2021-47223

  1. Yack CVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-47223

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

I

n the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst null pointer dereference This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path.

References
Link Resource
https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 Patch
https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f Patch
https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c Patch
https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d Patch
https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 Patch
https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 Patch
https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 Patch
https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f Patch
https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c Patch
https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d Patch
https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 Patch
https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc6:*:*:*:*:*:*
History

03 Feb 2025, 16:11

Type Values Removed Values Added
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
CPE cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
References () https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 - () https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 - Patch
References () https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f - () https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f - Patch
References () https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c - () https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c - Patch
References () https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d - () https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d - Patch
References () https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 - () https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 - Patch
References () https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 - () https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 - Patch
CWE CWE-476

21 Nov 2024, 06:35

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: bridge: corrige la desreferencia del puntero null del túnel vlan dst Este parche corrige una desreferencia del puntero null de Tunnel_dst debido al acceso sin bloqueo en la ruta de salida del túnel. Al eliminar un túnel VLAN, el puntero Tunnel_dst se establece en NULL sin esperar un período de gracia (es decir, mientras aún se puede utilizar) y los paquetes que salen lo desreferencian sin verificarlo. Use READ/WRITE_ONCE para anotar el uso sin bloqueo de Tunnel_id, use RCU para acceder a Tunnel_dst y asegúrese de que se lea solo una vez y se verifique en la ruta de salida. El dst ya está correctamente protegido por la RCU, por lo que no necesitamos hacer nada sofisticado más que asegurarnos de que Tunnel_id y Tunnel_dst se lean solo una vez y se verifiquen en la ruta de salida.
References () https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 - () https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 -
References () https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f - () https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f -
References () https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c - () https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c -
References () https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d - () https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d -
References () https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 - () https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 -
References () https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 - () https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 -

21 May 2024, 15:15

Type Values Removed Values Added
New CVE
Information

Published : 2024-05-21 15:15

Updated : 2025-02-03 16:11

NVD link : CVE-2021-47223

Mitre link : CVE-2021-47223

CVE.ORG link : CVE-2021-47223

JSON object : View

Products Affected

linux

CWE
CWE-476

NULL Pointer Dereference