Home/CVE/Apache Flink Improper Access Control Vulnerability
CVE

CVE-2020-17519

Apache Flink Improper Access Control Vulnerability

A change introduced in Apache Flink 1.11.0 (and released in 1.11.1 and 1.11.2 as well) allows attackers to read any file on the local filesystem of the JobManager through the REST interface of the JobManager process. Access is restricted to files accessible by the JobManager process. All users should upgrade to Flink 1.11.3 or 1.12.0 if their Flink instance(s) are exposed.

The issue was fixed in commit b561010b0ee741543c3953306037f00d7a9f0801 from apache/flink:master.

HIGH · CVSS 7.5 ⚠ CISA KEV EPSS 0.94331
Act now
  • Listed on CISA KEV (known exploited in the wild)
  • SSVC exploitation status: active
  • EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
  • EPSS percentile: top 0% of all CVEs by exploitation likelihood
  • Public exploit or PoC is available
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬢

Required Remediation

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

⬡

Weakness Classification

CWE-552Files or Directories Accessible to External Parties
CWE-552Files or Directories Accessible to External Parties
▤

Affected Products & Versions

1
apache flink>= 1.11.0 and < 1.11.3
▤

Affected Packages

2
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Maven org.apache.flink:flink-runtime_2.11 HIGH fixed in 1.11.3
Maven org.apache.flink:flink-runtime_2.12 HIGH fixed in 1.11.3
⚠

Public Exploits & PoCs

3
webappsApache Flink 1.11.0 - Unauthenticated Arbitrary File Read (Metasploit)verified
nucleiApache Flink - Local File Inclusionhigh
pocpacketstormsecurity.com · Apache-Flink-1.11.0-Arbitrary-File-Read-Directory-Travers...packetstormsecurity.com
◈

Detection Rules (IDS/IPS)

1
et-openET WEB_SPECIFIC_APPS Apache Flink Arbitrary File Read Attempt (CVE-2020-17519)attempted-recon
Open rulesets (ET Open, Snort Community, abuse.ch) link to source. Commercial rulesets are reference-only.
▣

Scoring & Timeline

7.5
HIGH · CVSS v3.1 · security@apache.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD05 Jan 2021 · 12:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
SSVC triage · cisa-vulnrichment
Exploitation
active
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

1
cisaKEV-CVE-2020-17519
🔗

References & Sources

16
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
http://www.openwall.com/lists/oss-security/2021/01/05/2Mailing ListThird Party Advisory
https://lists.apache.org/thread.html/r0a433be10676f4fe97ca423d08f914e0ead341c901216f292d2bbe83%40%3Cissues.flink.apache.org%3EMailing List
https://lists.apache.org/thread.html/r1125f3044a0946d1e7e6f125a6170b58d413ebd4a95157e4608041c7%40%3Cannounce.apache.org%3EMailing List
https://lists.apache.org/thread.html/r229167538863518738e02f4c1c5a8bb34c1d45dadcc97adf6676b0c1%40%3Cdev.flink.apache.org%3EIssue Tracking
https://lists.apache.org/thread.html/r26fcdd4fe288323006253437ebc4dd6fdfadfb5e93465a0e4f68420d%40%3Cuser-zh.flink.apache.org%3EIssue Tracking
https://lists.apache.org/thread.html/r28f17e564950d663e68cc6fe75756012dda62ac623766bb9bc5e7034%40%3Cissues.flink.apache.org%3EIssue Tracking
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