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HIGH · CVSS 7.5 CISA Known Exploited Vulnerability

CVE-2020-17519

Apache Flink Improper Access Control Vulnerability

Apache Flink

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.

CVSS
7.5
HIGH
EPSS
97.8%
30-day exploitation
Ransomware groups
0
recorded exploiting
Published
5 Jan 2021
CWE-552

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 23 May 2024. US federal agencies were required to remediate it by 13 June 2024.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 97.8%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Frequently asked questions

Is CVE-2020-17519 being exploited by ransomware groups?

No ransomware group in this database is currently recorded as exploiting CVE-2020-17519.

What does CVE-2020-17519 affect?

CVE-2020-17519 affects Apache Flink. 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.

How severe is CVE-2020-17519?

CVE-2020-17519 is rated HIGH with a CVSS base score of 7.5. EPSS puts the probability of exploitation in the next 30 days at 97.8%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 13 June 2024.

How should organisations respond to CVE-2020-17519?

Apply the vendor patch for Apache Flink as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.