← Back
UBUNTU-CVE-2021-27364
Vulnerability in linux (UBUNTU-CVE-2021-27364)
Summary
vulnerability in linux (UBUNTU-CVE-2021-27364). Confidential information can be exposed externally. Mitigation: upgrade to `3.13.0-185.236` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **UBUNTU-CVE-2021-27364** has been found in linux.
Confidential information can be exposed externally. CVSS score: ?/10.
What to do: upgrade linux to **3.13.0-185.236** or later.
If unsure, ask your IT team or search "linux UBUNTU-CVE-2021-27364" on the vendor's site.
UBUNTU-CVE-2021-27364 (linux) —
Attack vector: local / no user interaction
Patched: `3.13.0-185.236` — 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.
📍 Affected scope
linux — .
🔥 Severity
Severity: ?. Confidential information can be exposed externally
🔧 How to fix
Update to **3.13.0-185.236**.
🛡️ 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 (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify 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。
-
6Apply patch patch
Upgrade linux to 3.13.0-185.236ステージング環境で 3.13.0-185.236 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
-
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:14.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.13.0-185.236"}]}]
Ubuntu:Pro:14.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1088.92"}]}]
Ubuntu:Pro:14.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1110.122~14.04.1"}]}]
Ubuntu:Pro:14.04:LTS
linux-lts-xenial
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-206.238~14.04.1"}]}]
Ubuntu:16.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-206.238"}]}]
Ubuntu:16.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1124.138"}]}]
Ubuntu:16.04:LTS
linux-aws-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1096.103~16.04.1"}]}]
Ubuntu:16.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1110.122~16.04.1"}]}]
Ubuntu:16.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1095.108~16.04.1"}]}]
Ubuntu:16.04:LTS
linux-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-139.143~16.04.1"}]}]
Ubuntu:16.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1090.99"}]}]
Ubuntu:16.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1067.75~16.04.1"}]}]
Ubuntu:16.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1148.158"}]}]
Ubuntu:16.04:LTS
linux-snapdragon
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1152.162"}]}]
Ubuntu:16.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:16.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-139.143"}]}]
Ubuntu:18.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1096.103"}]}]
Ubuntu:18.04:LTS
linux-aws-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1041.43~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-azure-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1110.122"}]}]
Ubuntu:18.04:LTS
linux-azure-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1043.45~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-dell300x
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1015.19"}]}]
Ubuntu:18.04:LTS
linux-gcp-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1095.108"}]}]
Ubuntu:18.04:LTS
linux-gcp-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1040.43~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-gke-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.3.0-1041.44"}]}]
Ubuntu:18.04:LTS
linux-gke-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1039.41~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-gkeop-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1012.13~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.3.0-72.68"}]}]
Ubuntu:18.04:LTS
linux-hwe-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-70.78~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1087.89"}]}]
Ubuntu:18.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1067.75"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1041.44~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-raspi-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1032.35~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1081.86"}]}]
Ubuntu:18.04:LTS
linux-raspi2-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.3.0-1038.40"}]}]
Ubuntu:18.04:LTS
linux-snapdragon
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1098.107"}]}]
Ubuntu:18.04:LTS
linux-aws-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-aws-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gke-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oem
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2039.41"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2022.25"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1055.63"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-70.78"}]}]
Ubuntu:20.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1041.43"}]}]
Ubuntu:20.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1043.45"}]}]
Ubuntu:20.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1040.43"}]}]
Ubuntu:20.04:LTS
linux-gke
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1039.41"}]}]
Ubuntu:20.04:LTS
linux-gkeop
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1012.13"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.8.0-48.54~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1036.37"}]}]
Ubuntu:20.04:LTS
linux-oem-5.10
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.0-1019.20"}]}]
Ubuntu:20.04:LTS
linux-oem-5.6
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.6.0-1052.56"}]}]
Ubuntu:20.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1041.44"}]}]
Ubuntu:20.04:LTS
linux-raspi
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1032.35"}]}]
Ubuntu:20.04:LTS
linux-riscv-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.8.0-20.22~20.04.1"}]}]
Ubuntu:Pro:20.04:LTS
linux-azure-fde-5.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1069.73+fips2"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.76+fips1"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1067.71~20.04.1"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-intel-iot-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-raspi-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:26.04
linux-nvidia
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
References
- advisory https://ubuntu.com/security/notices/USN-4883-1
- advisory https://ubuntu.com/security/notices/USN-4887-1
- advisory https://ubuntu.com/security/notices/USN-4889-1
- advisory https://ubuntu.com/security/notices/USN-4901-1
- report https://ubuntu.com/security/CVE-2021-27364
- report https://git.kernel.org/linus/688e8128b7a92df982709a4137ea4588d16f24aa
- report https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=688e8128b7a92df982709a4137ea4588d16f24aa
- report https://www.openwall.com/lists/oss-security/2021/03/06/1
- report https://github.com/grimm-co/NotQuite0DayFriday/tree/trunk/2021.03.12-linux-iscsi
- report https://www.cve.org/CVERecord?id=CVE-2021-27364