Vulnerability in Kernel (CVE-2023-53685)

Summary

Vulnerability in Kernel (CVE-2023-53685). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.1.30, 6.3.4 or later.

Original description

The description as published by the source.

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

tun: Fix memory leak for detached NAPI queue.

syzkaller reported [0] memory leaks of sk and skb related to the TUN
device with no repro, but we can reproduce it easily with:

struct ifreq ifr = {}
int fd_tun, fd_tmp;
char buf[4] = {};

fd_tun = openat(AT_FDCWD, "/dev/net/tun", O_WRONLY, 0);
ifr.ifr_flags = IFF_TUN | IFF_NAPI | IFF_MULTI_QUEUE;
ioctl(fd_tun, TUNSETIFF, &ifr);

ifr.ifr_flags = IFF_DETACH_QUEUE;
ioctl(fd_tun, TUNSETQUEUE, &ifr);

fd_tmp = socket(AF_PACKET, SOCK_PACKET, 0);
ifr.ifr_flags = IFF_UP;
ioctl(fd_tmp, SIOCSIFFLAGS, &ifr);

write(fd_tun, buf, sizeof(buf));
close(fd_tun);

If we enable NAPI and multi-queue on a TUN device, we can put skb into
tfile->sk.sk_write_queue after the queue is detached. We should prevent
it by checking tfile->detached before queuing skb.

Note this must be done under tfile->sk.sk_write_queue.lock because write()
and ioctl(IFF_DETACH_QUEUE) can run concurrently. Otherwise, there would
be a small race window:

Another solution is to call tun_queue_purge() when cl…

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-2023-53685 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.1.30, 6.3.4 or later.
If unsure, ask your IT team or search "Kernel CVE-2023-53685" on the vendor's site.

CVE-2023-53685 (Kernel)
Patched: 6.1.30, 6.3.4 — 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 6.1.30, 6.3.4.

🛡️ 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 6.1.30, 6.3.4
```
ステージング環境で 6.1.30, 6.3.4 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":"3.8.0"},{"fixed":"6.1.30"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.3.4"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2023-53685 linux
Ubuntu UBUNTU-CVE-2023-53685 linux