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                             CERT-Renater

                 Note d'Information No. 2021/VULN344
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DATE                : 02/07/2021

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running Apache Druid versions prior to
                                       0.21.0.

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http://mail-archives.apache.org/mod_mbox/druid-dev/202107.mbox/%3c09e97049-8a5f-595b-70f2-5a9281c4adc7@apache.org%3e
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CVE-2021-26920: Apache Druid: The HTTP inputSource allows authenticated
users to read data from other sources than intended


Severity: low

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.


Mitigation:

Users can avoid the issue by upgrading to 0.21.0 or a higher version.


In an earlier version than 0.21.0, 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.


Credit:

This issue was discovered by chybeta from the Security Team of Alibaba
Cloud.


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