CVE-2021-29447
MediumPublic exploitA user with the ability to upload files (like an Author) can exploit an XML parsing issue in the Media Library leading to XXE attacks.
Published Apr 15, 2021 · Updated Sep 21, 2026 · Also known as 9df45c8e-c040-4031-9c51-4c43d12f08b0, BIT-wordpress-2021-29447, BIT-wordpress-multisite-2021-29447, DEBIAN-CVE-2021-29447, DLA-2630-1, DSA-4896-1, GHSA-rv47-pc52-qrhh, UBUNTU-CVE-2021-29447
Key Facts
Patch immediately- CVE-2021-29447 is a medium-severity vulnerability (CVSS 6.5 v3.1) affecting Wordpress, Debian Linux, wordpress-multisite (bitnami) and 1 more product.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 86% probability of exploitation in the next 30 days.
- Fixed versions are available, including Wordpress 4.7.20, Wordpress 4.7.20+dfsg-1+deb9u1, Wordpress 5.0.12+dfsg1-0+deb10u1.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
86%
Higher than 99.7% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-29447 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Wordpress is an open source CMS. A user with the ability to upload files (like an Author) can exploit an XML parsing issue in the Media Library leading to XXE attacks. This requires WordPress installation to be using PHP 8. Access to internal files is possible in a successful XXE attack. This has been patched in WordPress version 5.7.1, along with the older affected versions via a minor release. We strongly recommend you keep auto-updates enabled.
Affected Products
26 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| WordpressWordpress | >= 5.6.0, >= 4.7 | 5.7.1 |
| Debian LinuxDebian | 10.0, 9.0 | n/a |
| wordpress-multisitebitnami | >= 5.6.0 | 5.7.1 |
| wordpress-develop | >= >= 5.6.0, < 5.7.1 | n/a |
Patched Releases
Wordpress
4.7.20, 4.7.20+dfsg-1+deb9u1, 5.0.12+dfsg1-0+deb10u1, 5.7.1, 5.7.1-1, 5.7.1+dfsg1-1
wordpress-multisite
5.7.1
Timeline
Publicly disclosed
Apr 15, 2021
Last updated
Sep 21, 2026
Weakness Type
- CWE-611 Improper Restriction of XML External Entity Reference
References
- advisoryhttp://packetstormsecurity.com/files/163148/XML-External-Entity-Via-MP3-File-Upload-On-WordPress.html
- advisoryhttps://github.com/WordPress/wordpress-develop/security/advisories/GHSA-rv47-pc52-qrhh
- advisory[debian-lts-announce] 20210421 [SECURITY] [DLA 2630-1] wordpress security update
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2021-29447
- advisoryhttps://ubuntu.com/security/CVE-2021-29447
FAQ
Common Questions.
Wordpress is an open source CMS.
Affected: Wordpress versions >= 5.6.0, >= 4.7; Debian Linux versions 10.0, 9.0; wordpress-multisite (bitnami) versions >= 5.6.0, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Wordpress 4.7.20, Wordpress 4.7.20+dfsg-1+deb9u1, Wordpress 5.0.12+dfsg1-0+deb10u1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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