`CVE-2021-36749` Druid

Affected software	Druid
Severity	6.5 Medium CVSS 3.1 2 scores
Fixed in	`0.22.0`
Weakness	Incorrect authorization (CWE-863)
Published	24 Sep 2021
Updated	17 Jun 2026

Description

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. This issue was previously mentioned as being fixed in 0.21.0 as per CVE-2021-26920 but was not fixed in 0.21.0 or 0.21.1.

CWE-668

Exploitation status

Exploited

Real-world exploitation reported by VulnCheck KEV. CISA has not confirmed it.

CISA KEV not listed
VulnCheck KEV listed Exploitation reported in the wild. 1 citation · honeypot sightings · 4 exploits · earliest 2022-03-20.
CISA Vulnrichment no assessment published
Indexed PoC 5 indexed Published artifacts you can open, in GitHub PoC, Nuclei; first seen 2021-05-22.
EPSS 81% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99.6% of all scored CVEs.

VulnCheck KEV

Exploitation evidence from VulnCheck Known Exploited Vulnerabilities (VulnCheck KEV), used under VulnCheck's community terms. View CVE-2021-36749 in VulnCheck (free account).

Evidence	Source	Detail	Date
Honeypot sighting	SANS DShield sensors	Exploitation attempts seen on 1 day	2022-03-20
Reported exploitation	unit42.paloaltonetworks.com	/network-security-trends-cross-site-scripting	2022-05-31
Exploit reference	VulnCheck XDB e4e9ac13414a	Exploit type: infoleak	2021-05-22
Exploit reference	VulnCheck XDB d9494fbeed7f	Exploit type: infoleak	2021-10-14
Exploit reference	VulnCheck XDB 65e8166e235d	Exploit type: infoleak	2021-12-12
Exploit reference	VulnCheck XDB 9f4e61cec1a9	Exploit type: info-leak	2021-12-12

Evidence

Source

Detail

Date

Honeypot sighting

SANS DShield sensors

Exploitation attempts seen on 1 day

2022-03-20

Reported exploitation

unit42.paloaltonetworks.com

/network-security-trends-cross-site-scripting

2022-05-31

Exploit reference

VulnCheck XDB e4e9ac13414a

Exploit type: infoleak

2021-05-22

Exploit reference

VulnCheck XDB d9494fbeed7f

Exploit type: infoleak

2021-10-14

Exploit reference

VulnCheck XDB 65e8166e235d

Exploit type: infoleak

2021-12-12

Exploit reference

VulnCheck XDB 9f4e61cec1a9

Exploit type: info-leak

2021-12-12

2 of these are GitHub repositories with fewer than 5 stars. They are listed for reference and don't count toward the exploitation status above.

Index	Artifact	Stars	First seen
GitHub PoC	漏洞POC、EXP合集，持续更新。Apache Druid-任意文件读取（CVE-2021-36749）、ConfluenceRCE（CVE-2021-26084）、ZeroShell防火墙RCE（CVE-2019-12725）、ApacheSolr任意文件读取、蓝凌OA任意文件读取、phpStudyRCE、ShowDoc任意文件上传、原创先锋后台未授权、Kyan账号密码泄露、TerraMasterTos任意文件读取、TamronOS-IPTV系统RCE、Wayos防火墙账号密码泄露	177	2021-05-22
GitHub PoC	Apache Druid 任意文件读取	33	2021-10-14
GitHub PoC	CVE-2021-36749 Docker 漏洞复现	1	2021-11-21
GitHub PoC	Apache Druid LoadData 任意文件读取漏洞 / Code By:Jun_sheng		2021-12-12
Nuclei	Apache Druid - Local File Inclusion

Waratek protection

Mitigation candidate

A kind of vulnerability Waratek's rules address, with exploit code published or exploitation reported. No rule exists and none is planned yet. The decision below says what we found to build a rule from.

Protection none
Action unverified
Review automated Inferred
Record active

Decided by	The affected package being open source on Maven, so the fix can be read
Finding	This CVE affects an open-source Java library published on Maven Central (Maven packages: org.apache.druid:druid-core), so it is squarely in ARMR's territory and the source needed to understand the defect is public. That makes it a candidate for an ARMR patch rule. No rule exists and none is scheduled: the diff between the affected and fixed versions has not been read, and a closer look may find no hook point ARMR can act on.

Decided by

The affected package being open source on Maven, so the fix can be read

Finding

This CVE affects an open-source Java library published on Maven Central (Maven packages: org.apache.druid:druid-core), so it is squarely in ARMR's territory and the source needed to understand the defect is public. That makes it a candidate for an ARMR patch rule. No rule exists and none is scheduled: the diff between the affected and fixed versions has not been read, and a closer look may find no hook point ARMR can act on.

CVSS

6.5 MEDIUM v3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N 2 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 6.5 MEDIUM CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N NVD Primary published

CVSS 2.0 4.0 none AV:N/AC:L/Au:S/C:P/I:N/A:N NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	6.5	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`	NVD	Primary	published
CVSS 2.0	4.0	none	`AV:N/AC:L/Au:S/C:P/I:N/A:N`	NVD	Primary

Affected software and releases

Maven packages

Affected and fixed versions, from OSV.dev

Package Introduced Fixed Last affected

org.apache.druid:druid-core 0 0.22.0 unbounded

Package	Introduced	Fixed	Last affected
`org.apache.druid:druid-core`	0	`0.22.0`	unbounded

Products and versions

2 products, 2 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	apache	druid	generic	＜ 0.22.0
osv	org.apache.druid	druid-core	generic	＜ 0.22.0

Source

Vendor

Product

Scheme

Affected versions

nvd

apache

druid

generic

＜ 0.22.0

osv

org.apache.druid

druid-core

generic

＜ 0.22.0

References

URL	Tags
https://github.com/advisories/GHSA-793h-6f7r-6qvm	ADVISORY
https://lists.apache.org/thread.html/r304dfe56a5dfe1b2d9166b24d2c74ad1c6730338b20aef77a00ed2be@%3Cannounce.apache.org%3E	WEB
https://lists.apache.org/thread.html/rc9400a70d0ec5cdb8a3486fc5ddb0b5282961c0b63e764abfbcb9f5d%40%3Cdev.druid.apache.org%3E	WEB
https://lists.apache.org/thread.html/r304dfe56a5dfe1b2d9166b24d2c74ad1c6730338b20aef77a00ed2be%40%3Cannounce.apache.org%3E

URL

Timeline

Published	2021-09-24	By the CVE Program.
VulnCheck KEV: earliest evidence	2022-03-20	Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.
VulnCheck KEV: latest evidence	2022-05-31	Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.
NVD record modified	2026-06-17	NVD's own last-modified date for this record.

Published

2021-09-24

By the CVE Program.

VulnCheck KEV: earliest evidence

2022-03-20

Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.

VulnCheck KEV: latest evidence

2022-05-31

Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.

NVD record modified

2026-06-17

NVD's own last-modified date for this record.

How VRT decided (17 of 24 rules ran)

17 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification no match Manual classification of this CVE in the legacy dataset

6 non-java-upstream no match A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component no match The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side no match Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven matched In scope Maven packages: org.apache.druid:druid-core

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint no match A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven decided it matched Mitigation candidate Open-source Maven artifact indexed by OSV (Maven packages: org.apache.druid:druid-core). The source is public, which makes an ARMR patch rule a candidate; nothing here establishes that one can be written.

19 poc-derivable skipped An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit skipped Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match no match A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc skipped Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold withheld VulnCheck KEV-listed (1 written report(s), earliest 2022-05-31; seen by SANS DShield honeypots on 1 day(s) from 2022-03-20 to 2022-03-20) — exploitation is reported, so it requires review regardless of severity

24 no-exploit-published no match A CISA or VulnCheck KEV listing, a CISA verdict of active exploitation, a reviewed exploit catalogue, or a GitHub PoC with 5 or more stars carries this CVE — exploit code is in use or published, so it stays a candidate

Products the scope rules checked

The products this CVE's record names, and whether VRT tracks each one. The scope rules decided on these.

Vendor Product Tracked CPE Source

apache druid not tracked cpe:2.3:a:apache:druid:*:*:*:*:*:*:*:*

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