Vulnerability in Kernel (CVE-2023-52527)

Summary

Vulnerability in Kernel (CVE-2023-52527). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.135, 6.1.57, 6.5.7 or later.

Original description

The description as published by the source.

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

ipv4, ipv6: Fix handling of transhdrlen in __ip{,6}_append_data()

Including the transhdrlen in length is a problem when the packet is
partially filled (e.g. something like send(MSG_MORE) happened previously)
when appending to an IPv4 or IPv6 packet as we don't want to repeat the
transport header or account for it twice. This can happen under some
circumstances, such as splicing into an L2TP socket.

The symptom observed is a warning in __ip6_append_data():

WARNING: CPU: 1 PID: 5042 at net/ipv6/ip6_output.c:1800 __ip6_append_data.isra.0+0x1be8/0x47f0 net/ipv6/ip6_output.c:1800

that occurs when MSG_SPLICE_PAGES is used to append more data to an already
partially occupied skbuff. The warning occurs when 'copy' is larger than
the amount of data in the message iterator. This is because the requested
length includes the transport header length when it shouldn't. This can be
triggered by, for example:

    sfd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_L2TP);
    bind(sfd, ...); // ::1
    connect(sfd, ...); // ::1 port 7
    send(sfd, buffer, 4100, MSG_MORE);
    sendfile(sfd, dfd, NULL, 1024);

Fix this by only adding transhdrlen into the length if the write queue is
empty in l2tp_ip6_sendmsg(), analogously to how UDP does things.

l2tp_ip_sendmsg() looks like it won't suffer from this problem as it builds
the UDP packet itself.

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-2023-52527 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.135, 6.1.57, 6.5.7 or later.
If unsure, ask your IT team or search "Kernel CVE-2023-52527" on the vendor's site.

CVE-2023-52527 (Kernel)
Patched: 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.135, 6.1.57, 6.5.7 — 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 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.135, 6.1.57, 6.5.7.

🛡️ 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 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.135, 6.1.57, 6.5.7
```
ステージング環境で 4.14.327, 4.19.296, 5.4.258, 5.10.198, 5.15.135, 6.1.57, 6.5.7 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":"3.5.0"},{"fixed":"4.14.327"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"4.19.296"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.4.258"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.198"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.135"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.57"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.5.7"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2023-52527 linux Fixed in: 5.10.205-1
Ubuntu UBUNTU-CVE-2023-52527 linux-aws Fixed in: 4.4.0-1136.142