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UBUNTU-CVE-2023-38037
Vulnerability in rails (UBUNTU-CVE-2023-38037)
Summary
vulnerability in rails (UBUNTU-CVE-2023-38037). Confidential information can be exposed externally. Exploitable via ``umask``.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **UBUNTU-CVE-2023-38037** has been found in rails.
Attackers can target a specific entry point like ``umask`` over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: ?/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "rails UBUNTU-CVE-2023-38037" on the vendor's site.
UBUNTU-CVE-2023-38037 (rails) —
Attack vector: local
Attack surface: `umask`
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 rails. Attackers reach the vulnerable code path via ``umask`` without authentication.
📍 Affected scope
rails — . Attack surface: `umask`.
🔥 Severity
Severity: ?. Confidential information can be exposed externally
🔧 How to fix
Update to the patched release per vendor advisory.
🛡️ 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 'rails' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'rails' . | 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 `rails` を grep し、稼働しているサービス・バージョンを把握する。
-
7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
Ubuntu:Pro:16.04:LTS
rails
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:18.04:LTS
rails
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:20.04:LTS
rails
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:22.04:LTS
rails
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
rails
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:25.10
rails
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:26.04:LTS
rails
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
References
- report https://ubuntu.com/security/CVE-2023-38037
- report https://github.com/advisories/GHSA-cr5q-6q9f-rq6q
- report https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activesupport/CVE-2023-38037.yml
- report https://github.com/rails/rails/commit/a21d6edf35a60383dfa6c4da49e4b1aef5f00731
- report https://github.com/rails/rails/commit/c85cc667ebfd3c270df37c7575d580ea6462e12f
- report https://www.cve.org/CVERecord?id=CVE-2023-38037