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CVE-2021-23385
Open Redirect in flask-security (CVE-2021-23385)
Summary
vulnerability in flask-security (CVE-2021-23385). Risk of unauthorized operations or information disclosure.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2021-23385** has been found in flask-security.
Risk of unauthorized operations or information disclosure. CVSS score: ?/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "flask-security CVE-2021-23385" on the vendor's site.
CVE-2021-23385 (flask-security) — CWE-601 /
Attack vector: remote (network-reachable) / unauthenticated
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** (CWE-601) exists in flask-security.
📍 Affected scope
flask-security — .
🔥 Severity
Severity: ?. Risk of unauthorized operations or information disclosure
🔧 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 'flask-security' .` 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 'flask-security' . | 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 `flask-security` を grep し、稼働しているサービス・バージョンを把握する。
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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
PyPI
flask-security
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.0.0"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2021-23385
- advisory https://github.com/advisories/GHSA-cg8c-gc2j-2wf7
- advisory https://snyk.io/blog/url-confusion-vulnerabilities/
- package https://github.com/mattupstate/flask-security
- package https://pypi.org/project/flask-security
- report https://security.snyk.io/vuln/SNYK-PYTHON-FLASKSECURITY-1293234
- web https://snyk.io/blog/url-confusion-vulnerabilities
- web https://lists.debian.org/debian-lts-announce/2023/08/msg00034.html