Vulnerability in Kernel (CVE-2025-38666)

Summary

Vulnerability in Kernel (CVE-2025-38666). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.101, 6.12.41, 6.15.9 or later.

Original description

The description as published by the source.

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

net: appletalk: Fix use-after-free in AARP proxy probe

The AARP proxy‐probe routine (aarp_proxy_probe_network) sends a probe,
releases the aarp_lock, sleeps, then re-acquires the lock. During that
window an expire timer thread (__aarp_expire_timer) can remove and
kfree() the same entry, leading to a use-after-free.

race condition:

     cpu 0                          |            cpu 1
atalk_sendmsg()                     |   atif_proxy_probe_device()
aarp_send_ddp()                     |   aarp_proxy_probe_network()
mod_timer()                         |   lock(aarp_lock) // LOCK!!
timeout around 200ms                |   alloc(aarp_entry)
and then call                       |   proxies[hash] = aarp_entry
aarp_expire_timeout()               |   aarp_send_probe()
                                    |   unlock(aarp_lock) // UNLOCK!!
lock(aarp_lock) // LOCK!!           |   msleep(100);
__aarp_expire_timer(&proxies[ct])   |
free(aarp_entry)                    |
unlock(aarp_lock) // UNLOCK!!       |
                                    |   lock(aarp_lock) // LOCK!!
                                    |   UAF aarp_entry !!

==================================================================
BUG: KASAN: slab-use-after-free in aarp_proxy_probe_network+0x560/0x630 net/appletalk/aarp.c:493
Read of size 4 at addr ffff8880123aa360 by task repro/13278

CPU: 3 UID: 0…

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-2025-38666 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.101, 6.12.41, 6.15.9 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-38666" on the vendor's site.

CVE-2025-38666 (Kernel)
Patched: 5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.101, 6.12.41, 6.15.9 — 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 5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.101, 6.12.41, 6.15.9.

🛡️ 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 5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.101, 6.12.41, 6.15.9
```
ステージング環境で 5.4.297, 5.10.241, 5.15.190, 6.1.148, 6.6.101, 6.12.41, 6.15.9 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":"2.6.12"},{"fixed":"5.4.297"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.241"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.190"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.41"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.15.9"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-38666 linux-lts Fixed in: 6.1.151-r0
Debian DEBIAN-CVE-2025-38666 linux Fixed in: 5.10.244-1
Ubuntu UBUNTU-CVE-2025-38666 linux