CVE-2021-47223
Linux Kernel Bridge VLAN Tunnel Null Pointer Dereference
Description
In 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.
INFO
Published Date :
May 21, 2024, 3:15 p.m.
Last Modified :
Feb. 3, 2025, 4:11 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47223.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47223 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47223 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 03, 2025
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NIST CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.11 up to (excluding) 4.14.238 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.15 up to (excluding) 4.19.196 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.128 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5 up to (excluding) 5.10.46 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.12.13 *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:*:*:*:*:*:* Changed Reference Type https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 No Types Assigned https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 Patch Changed Reference Type https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 No Types Assigned https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 Patch Changed Reference Type https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f No Types Assigned https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f Patch Changed Reference Type https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f No Types Assigned https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f Patch Changed Reference Type https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c No Types Assigned https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c Patch Changed Reference Type https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c No Types Assigned https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c Patch Changed Reference Type https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d No Types Assigned https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d Patch Changed Reference Type https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d No Types Assigned https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d Patch Changed Reference Type https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 No Types Assigned https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 Patch Changed Reference Type https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 No Types Assigned https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 Patch Changed Reference Type https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 No Types Assigned https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 Patch Changed Reference Type https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 No Types Assigned https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 Added Reference https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f Added Reference https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c Added Reference https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d Added Reference https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 Added Reference https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 21, 2024
Action Type Old Value New Value Added Description In 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. Added Reference kernel.org https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47223 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47223
weaknesses.