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UBUNTU-CVE-2023-52676

Vulnerability in linux (UBUNTU-CVE-2023-52676)

Summary

Vulnerability in linux (UBUNTU-CVE-2023-52676). Risk of unauthorized operations or information disclosure. Exploitable via int. Mitigation: upgrade to 6.5.0-1022.23~22.04.1 or later.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved: bpf: Guard stack limits against 32bit overflow This patch promotes the arithmetic around checking stack bounds to be done in the 64-bit domain, instead of the current 32bit. The arithmetic implies adding together a 64-bit register with a int offset. The register was checked to be below 1<<29 when it was variable, but not when it was fixed. The offset either comes from an instruction (in which case it is 16 bit), from another register (in which case the caller checked it to be below 1<<29 [1]), or from the size of an argument to a kfunc (in which case it can be a u32 [2]). Between the register being inconsistently checked to be below 1<<29, and the offset being up to an u32, it appears that we were open to overflowing the ints which were currently used for arithmetic. [1] https://github.com/torvalds/linux/blob/815fb87b753055df2d9e50f6cd80eb10235fe3e9/kernel/bpf/verifier.c#L7494-L7498 [2] https://github.com/torvalds/linux/blob/815fb87b753055df2d9e50f6cd80eb10235fe3e9/kernel/bpf/verifier.c#L11904

Source: OSV.dev (Open Source Vulnerabilities) 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 UBUNTU-CVE-2023-52676 has been found in linux.
Attackers can target a specific entry point like int over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade linux to 6.5.0-1022.23~22.04.1 or later.
If unsure, ask your IT team or search "linux UBUNTU-CVE-2023-52676" on the vendor's site.

UBUNTU-CVE-2023-52676 (linux)
Attack vector: local / no user interaction
Attack surface: int
Patched: 6.5.0-1022.23~22.04.1 — 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 linux. Attackers reach the vulnerable code path via int.

📍 Affected scope

Check the vendor advisory for the affected versions of linux. Attack surface: int.

🔥 Severity

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

🔧 How to fix

Update to 6.5.0-1022.23~22.04.1.

🛡️ 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 'linux' . 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 'linux' . | 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 linux 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 linux to 6.5.0-1022.23~22.04.1
```
ステージング環境で 6.5.0-1022.23~22.04.1 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。