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CVE-2020-17519
CISA KEV
high
[KEV] Vulnerability in Apache flink (CVE-2020-17519)
Summary
vulnerability in Apache flink (CVE-2020-17519). Confidential information can be exposed externally. Listed in CISA KEV — actively exploited.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2020-17519** has been found in Apache flink.
Confidential information can be exposed externally. CVSS score: ?/10.
Note: CISA has officially confirmed this is **actively exploited in the wild**. Treat it with elevated urgency.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Apache flink CVE-2020-17519" on the vendor's site.
CVE-2020-17519 (Apache flink) — CWE-552 /
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Listed in CISA KEV — actively exploited, treat as top priority.
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-552) exists in Apache flink.
📍 Affected scope
Apache flink — .
🔥 Severity
Severity: High. Confidential information can be exposed externally **Listed in CISA KEV** — actively exploited in the wild, treat as top priority.
🔧 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 'flink' .` 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
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1Identify exposure identify
grep -r 'flink' . | 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 `flink` 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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4Consider incident declaration escalate
Notify SOC / on-callCISA KEV登録済 = 実環境で悪用が観測されている。Step 3 で兆候があればインシデント対応宣言、無くてもパッチ適用までWAF強化を最優先で。
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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。
References
- advisory NVD
- advisory http://www.openwall.com/lists/oss-security/2021/01/05/2
- advisory https://lists.apache.org/thread.html/r4e1b72bfa789ea5bc20b8afe56119200ed25bdab0eb80d664fa5bfe2%40%3Cdev.flink.apache.org%3E
- advisory https://lists.apache.org/thread.html/r6843202556a6d0bce9607ebc02e303f68fc88e9038235598bde3b50d%40%3Cannounce.apache.org%3E
- advisory https://lists.apache.org/thread.html/r6843202556a6d0bce9607ebc02e303f68fc88e9038235598bde3b50d%40%3Cdev.flink.apache.org%3E
- advisory https://lists.apache.org/thread.html/r88b55f3ebf1f8f4e1cc61f030252aaef4b77060b56557a243abb92a1%40%3Cissues.flink.apache.org%3E
- advisory https://lists.apache.org/thread.html/r88f427865fb6aa6e6378efe07632a1906b430365e15e3b9621aabe1d%40%3Cissues.flink.apache.org%3E
- report https://lists.apache.org/thread.html/r229167538863518738e02f4c1c5a8bb34c1d45dadcc97adf6676b0c1%40%3Cdev.flink.apache.org%3E
- report https://lists.apache.org/thread.html/r26fcdd4fe288323006253437ebc4dd6fdfadfb5e93465a0e4f68420d%40%3Cuser-zh.flink.apache.org%3E
- report https://lists.apache.org/thread.html/r28f17e564950d663e68cc6fe75756012dda62ac623766bb9bc5e7034%40%3Cissues.flink.apache.org%3E
- report https://lists.apache.org/thread.html/r2fc60b30557e4a537c2a6293023049bd1c49fd92b518309aa85a0398%40%3Cissues.flink.apache.org%3E
- report https://lists.apache.org/thread.html/r6843202556a6d0bce9607ebc02e303f68fc88e9038235598bde3b50d%40%3Cuser.flink.apache.org%3E
- report https://lists.apache.org/thread.html/ra8c96bf3ccb4e491f9ce87ba35f134b4449beb2a38d1ce28fd89001f%40%3Cdev.flink.apache.org%3E
- report http://packetstormsecurity.com/files/160849/Apache-Flink-1.11.0-Arbitrary-File-Read-Directory-Traversal.html
- web https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-17519
- web https://lists.apache.org/thread.html/r0a433be10676f4fe97ca423d08f914e0ead341c901216f292d2bbe83%40%3Cissues.flink.apache.org%3E
- web https://lists.apache.org/thread.html/r1125f3044a0946d1e7e6f125a6170b58d413ebd4a95157e4608041c7%40%3Cannounce.apache.org%3E
- web https://lists.apache.org/thread.html/r90890afea72a9571d666820b2fe5942a0a5f86be406fa31da3dd0922%40%3Cannounce.apache.org%3E