CVE-2021-26920Network attack vector

Local file disclosure via file URL dereference

Published Jul 2, 2021 · Updated Aug 3, 2024

CWE-610 in HTTP InputSource in Apache Druid 0.20.2 and earlier allows remote authenticated users to read server-local files. HTTP InputSource accepts a file URL and dereferences it with the Druid server process's file permissions instead of restricting the source to HTTP or HTTPS. Exposure arises when an intermediary application permits HTTP InputSource specifications but blocks Local InputSource, allowing the application-level restriction to be bypassed.

CVSS severity6.5
Medium
EPSS probability9.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CWE-610 in HTTP InputSource in Apache Druid 0.20.2 and earlier allows remote authenticated users to read server-local files. HTTP InputSource accepts a file URL and dereferences it with the Druid server process's file permissions instead of restricting the source to HTTP or HTTPS. Exposure arises when an intermediary application permits HTTP InputSource specifications but blocks Local InputSource, allowing the application-level restriction to be bypassed.

The record

CVE
CVE-2021-26920
Published
Jul 2, 2021
Updated
Aug 3, 2024
Vendor
The Apache Software Foundation
Product
Apache Druid
Classifications
CWE-610, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Apache Druid <=0.20.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Apache Software Foundation · Apache Druidversion=Apache Druid <=0.20.2

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-610Externally Controlled Reference to a Resource in Another Sphere
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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