Vulnerability in Kernel (CVE-2023-53021)

Summary

Vulnerability in Kernel (CVE-2023-53021). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 5.4.231, 5.10.166, 5.15.91, 6.1.9 or later.

Original description

The description as published by the source.

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

net/sched: sch_taprio: fix possible use-after-free

syzbot reported a nasty crash [1] in net_tx_action() which
made little sense until we got a repro.

This repro installs a taprio qdisc, but providing an
invalid TCA_RATE attribute.

qdisc_create() has to destroy the just initialized
taprio qdisc, and taprio_destroy() is called.

However, the hrtimer used by taprio had already fired,
therefore advance_sched() called __netif_schedule().

Then net_tx_action was trying to use a destroyed qdisc.

We can not undo the __netif_schedule(), so we must wait
until one cpu serviced the qdisc before we can proceed.

Many thanks to Alexander Potapenko for his help.

[1]
BUG: KMSAN: uninit-value in queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
BUG: KMSAN: uninit-value in do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
BUG: KMSAN: uninit-value in __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
BUG: KMSAN: uninit-value in _raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
__raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
_raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
spin_trylock include/linux/spinlock.h:359 [inline]
qdisc_run_begin include/net/sch_generic.h:187 [inline]
qdisc_run+0xee/0x540 include/net/pkt_sched.h:125
net…

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-2023-53021 has been found in Kernel.
Successful exploitation can lead to full system takeover.
What to do: upgrade Kernel to 5.4.231, 5.10.166, 5.15.91, 6.1.9 or later.
If unsure, ask your IT team or search "Kernel CVE-2023-53021" on the vendor's site.

CVE-2023-53021 (Kernel)
Attack vector: local / no user interaction
Patched: 5.4.231, 5.10.166, 5.15.91, 6.1.9 — 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: ?. Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 5.4.231, 5.10.166, 5.15.91, 6.1.9.

🛡️ 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 5.4.231, 5.10.166, 5.15.91, 6.1.9
```
ステージング環境で 5.4.231, 5.10.166, 5.15.91, 6.1.9 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":"4.20.0"},{"fixed":"5.4.231"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.166"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.9"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2023-53021 linux Fixed in: 5.10.178-1
Ubuntu UBUNTU-CVE-2023-53021 linux-hwe-edge