CVE-2021-29447Public exploitNetwork attack vector

Authenticated file disclosure via WAVE metadata parsing

Published Apr 15, 2021 · Updated Aug 3, 2024

XXE in the WordPress 5.6.0 through 5.7 Media Library allows remote authenticated users to read server files through crafted audio uploads. The getID3 XML2array method parses a WAVE file's attacker-controlled iXML chunk with LIBXML_NOENT, which substitutes external entities under PHP 8. Exploitation requires the upload_files capability, normally held by Authors, and supports blind file disclosure or server-side requests.

CVSS severity7.1
High
EPSS probability85.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE in the WordPress 5.6.0 through 5.7 Media Library allows remote authenticated users to read server files through crafted audio uploads. The getID3 XML2array method parses a WAVE file's attacker-controlled iXML chunk with LIBXML_NOENT, which substitutes external entities under PHP 8. Exploitation requires the upload_files capability, normally held by Authors, and supports blind file disclosure or server-side requests.

The record

CVE
CVE-2021-29447
Published
Apr 15, 2021
Updated
Aug 3, 2024
Vendor
WordPress.org
Product
WordPress
Classifications
CWE-611, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 15, 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=>= 5.6.0, < 5.7.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

WordPress.org · WordPressversion=>= 5.6.0, < 5.7.1

Published CVSS scores

7.1GitHub CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

Public exploit references

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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