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Fencer Vulns
medium 6.5

CVE-2021-26920 json

Apache Druid: The HTTP inputSource allows authenticated users to read data from other sources than intended

published 2021-07-02 5 y ago modified 2026-07-08 4 mo ago also CVE-2023-26920 , GHSA-793h-6f7r-6qvm , GHSA-x3cc-x39p-42qx , EUVD-2021-1614

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
9.5%
EPSS 9.5% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

In the Druid ingestion system, the InputSource is used for reading data from a certain data source. However, the HTTP InputSource allows authenticated users to read data from other sources than intended, such as the local file system, with the privileges of the Druid server process. This is not an elevation of privilege when users access Druid directly, since Druid also provides the Local InputSource, which allows the same level of access. But it is problematic when users interact with Druid indirectly through an application that allows users to specify the HTTP InputSource, but not the Local InputSource. In this case, users could bypass the application-level restriction by passing a file URL to the HTTP InputSource.

Patch / fix

  • npm fast-xml-parser 4.1.2
  • maven org.apache.druid:druid-core 0.21.0
  • apache druid 0.22.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-26920 updated cvss 6.5

druid: HTTP InputSource allows authenticated users to read data from other sources

  • Red Hat OpenShift Container Platform 4 openshift4/ose-metering-hive
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

9.50% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
npm fast-xml-parser
<4.1.2
4.1.2
maven org.apache.druid:druid-core
<0.21.0
0.21.0

Affected products

  • Apache Software Foundation Apache Druid

Classification

Weakness
  • CWE-610 Externally Controlled Reference to a Resource in Another Sphere
  • CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
  • CWE-863 Incorrect Authorization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.