Vulnerability in Kernel (CVE-2025-21973)

Summary

Vulnerability in Kernel (CVE-2025-21973). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.12.20, 6.13.8 or later.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

eth: bnxt: fix kernel panic in the bnxt_get_queue_stats{rx | tx}

When qstats-get operation is executed, callbacks of netdev_stats_ops
are called. The bnxt_get_queue_stats{rx | tx} collect per-queue stats
from sw_stats in the rings.
But {rx | tx | cp}_ring are allocated when the interface is up.
So, these rings are not allocated when the interface is down.

The qstats-get is allowed even if the interface is down. However,
the bnxt_get_queue_stats{rx | tx}() accesses cp_ring and tx_ring
without null check.
So, it needs to avoid accessing rings if the interface is down.

Reproducer:
ip link set $interface down
./cli.py --spec netdev.yaml --dump qstats-get
OR
ip link set $interface down
python ./stats.py

Splat looks like:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 1680fa067 P4D 1680fa067 PUD 16be3b067 PMD 0
Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 UID: 0 PID: 1495 Comm: python3 Not tainted 6.14.0-rc4+ #32 5cd0f999d5a15c574ac72b3e4b907341
Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021
RIP: 0010:bnxt_get_queue_stats_rx+0xf/0x70 [bnxt_en]
Code: c6 87 b5 18 00 00 02 eb a2 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 01
RSP: 0018:ffffabef43cdb7e0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffffffc04c8710 RCX: 0000000000000000
RDX: fff…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2025-21973 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.12.20, 6.13.8 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-21973" on the vendor's site.

CVE-2025-21973 (Kernel)
Patched: 6.12.20, 6.13.8 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.12.20, 6.13.8.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 6.12.20, 6.13.8
```
ステージング環境で 6.12.20, 6.13.8 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"6.9.0"},{"fixed":"6.12.20"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.13.8"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-21973 linux-lts Fixed in: 6.12.41-r0
Debian DEBIAN-CVE-2025-21973 linux Fixed in: 6.12.20-1