CVE-2020-17519

Apache Flink: Improper Access Control

As of , CVE-2020-17519 in Apache Flink is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch this week.

Exploited
Yes: CISA listed it on 23 May 2024
US federal deadline
13 June 202421 days after CISA listed it. US federal civilian agencies must fix it by then.
Used in ransomware campaigns
Not known to CISA
EPSS score
0.98Higher than 99% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
EPSS when listed
0.97 on 23 May 2024EPSS on the day CISA listed it.
Public exploit
1 Metasploit module and 1 Exploit-DB entry (1 verified)
Fix
Vendor advice: lists.apache.orgLinks below, from CISA's entry.

What CISA says to do

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

CISA's required action

  • lists.apache.orgThis vulnerability affects a common open-source component, third-party library, or a protocol used by different products. Please check…

What the flaw is

Apache Flink contains an improper access control vulnerability that allows an attacker to read any file on the local filesystem of the JobManager through its REST interface.

CISA's description

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.

The CVE record's description, from apache

CVE published
5 January 2021
Assigned by
apache
CVSS
9.1 Critical (CVSS 3.1, from CISA-ADP)
CWE-552
Files or Directories Accessible to External Parties
CISA SSVC, exploitation
active
CISA SSVC, automatable
yes
CISA SSVC, technical impact
partial

Timeline

  1. The CVE record was published.
  2. Exploit-DB published an exploit (EDB-ID 49398).
  3. CISA added it to its list of exploited vulnerabilities.
  4. The US federal deadline to fix it.

Public exploits

Facts from Metasploit's module list and Exploit-DB's index; we never copy exploit code.

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