cbcvebase.
CVE-2021-26920
published 2021-07-02

CVE-2021-26920: 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…

PriorityP274medium6.5CVSS 3.1
AVNACLPRLUINSUCHINAN
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
9.88%
95.1th percentile
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.

Affected

2 ranges
VendorProductVersion rangeFixed in
apachedruid< 0.22.00.22.0
apache_software_foundationapache_druid0.21.1 and earlier – 0.21.1

Detection & IOCsextracted from sources · hover to see the quote

url/druid/indexer/v1/sampler?for=connect
pathfile:///etc/passwd
  • Detect POST requests to the Druid sampler endpoint with a 'file://' URI scheme inside the HTTP InputSource 'uris' field, indicating an LFI attempt via the HTTP InputSource bypass.
  • Match response body for Unix passwd file patterns (e.g., 'root:.*:0:0:' or 'druid:*:1000:1000:') to confirm successful local file read via the vulnerability.
  • Flag any HTTP InputSource ingestion request where the 'uris' array contains a 'file://' scheme, as this is the core bypass technique — passing a file URL to the HTTP InputSource to read local files.
  • ·The vulnerability is only exploitable by authenticated users; unauthenticated access to the Druid API is required to be blocked at the network/application layer. The fix was incomplete in versions 0.21.0 and 0.21.1.
  • ·OpenShift Container Platform deployments of Druid (ose-metering-hive) are not affected because HTTP and HDFS InputSources are not included in that package.

CVSS provenance

nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
nvdv2.04.0MEDIUMAV:N/AC:L/Au:S/C:P/I:N/A:N
ghsa6.5MEDIUM
osv6.5MEDIUM
vulncheck6.5MEDIUM
vendor_redhat6.5MEDIUM
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