CVE-2021-22140Network attack vector

Host file disclosure via malicious sitemap XXE

Published May 13, 2021 · Updated Aug 3, 2024

XXE in Elastic App Search after 7.11.0 and before 7.12.0 allows remote attackers to read host files through a crafted sitemap.xml. Elastic has not identified the parser or disclosed how external entity resolution remains enabled during sitemap processing. The attacker must control a site selected for crawling; successful exploitation exposes files readable by the App Search process.

CVSS severity9.3
Critical
EPSS probability1.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE in Elastic App Search after 7.11.0 and before 7.12.0 allows remote attackers to read host files through a crafted sitemap.xml. Elastic has not identified the parser or disclosed how external entity resolution remains enabled during sitemap processing. The attacker must control a site selected for crawling; successful exploitation exposes files readable by the App Search process.

The record

CVE
CVE-2021-22140
Published
May 13, 2021
Updated
Aug 3, 2024
Vendor
Elastic
Product
Elastic App Search
Classifications
CWE-611, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 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=after 7.11.0 and before 7.12.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Elastic · Elastic App Searchversion=after 7.11.0 and before 7.12.0

Published CVSS scores

9.3ElasticCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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