CVE-2021-36749
Apache Druid: The HTTP inputSource allows authenticated users to read data from other sources than intended (incomplete fix of CVE-2021-26920)
- 6.5MediumCVSS base score
- 80.9%Exploitation in 30 daysEPSS · top 0.4% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 1Public exploitsMetasploit, Nuclei and Exploit-DB
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Nuclei template for it.
Show the exploits1
Nuclei templates1 template
- Apache Druid - Local File Inclusion (Nuclei template) (opens in a new tab)
http/cves/2021/CVE-2021-36749.yamlSeverity medium
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By apache
- 2 months later
· 2 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 80.9% · top 0.4% of all CVEs (11 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Affected products
Apache Software Foundation · Apache Druid
- affected 0.21.1 and earlier – ≤ 0.21.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.apache.druid:druid-coreGHSA-9p5g-vg43-mj5r (opens in a new tab)
What to do
Workaround: Users can avoid the issue by upgrading to 0.22.0 or a higher version. In an earlier version than 0.22.0, when the user application wants to restrict the access to the local file system, it should disallow all InputSources that can read local files, that is the Local, HTTP, and HDFS InputSources.
References
References2
- https://lists.apache.org/thread.html/rc9400a70d0ec5cdb8a3486fc5ddb0b5282961c0b63e764abfbcb9f5d%40%3Cdev.druid.apache.org%3E (opens in a new tab)x_refsource_MISCx_transferred
- [announce] 20210923 CVE-2021-36749: Apache Druid: The HTTP inputSource allows authenticated users to read data from other sources than intended (incomplete fix of CVE-2021-26920) (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-2026 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-9p5g-vg43-mj5r (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-36749)Record last updated .