BIT-wordpress-multisite-2024-31210: PHP file upload bypass via Plugin installer

Q: Which users and deployment types are affected?

The issue affects Administrator users on single-site installations and Super Admin users on Multisite installations. Lower-privileged users are not affected.

Q: What conditions are required for exploitation?

An affected administrative user must upload a non-ZIP file through the plugin installer, and WordPress must request FTP credentials to move the file outside the uploads directory. The RCE scenario additionally requires DISALLOW_FILE_EDIT to be set to true, where the user otherwise cannot execute arbitrary PHP code.

Q: Are default file-modification configurations affected?

Sites with DISALLOW_FILE_MODS set to true are not affected. Sites are also not affected when the administrative user does not need to provide FTP credentials or has access to valid FTP credentials.

Q: What can be done if patching is not immediately possible?

Set DISALLOW_FILE_MODS to true to prevent the affected file-modification path. Also avoid configurations that require administrators to enter FTP credentials for theme or plugin uploads.

Published Apr 4, 2024

Updated

WordPress is an open publishing platform for the Web. It's possible for a file of a type other than a zip file to be submitted as a new plugin by an administrative user on the Plugins -> Add New -> Upload Plugin screen in WordPress. If FTP credentials are requested for installation (in order to move the file into place outside of the uploads directory) then the uploaded file remains temporary available in the Media Library despite it not being allowed. If the DISALLOWFILEEDIT constant is set to true on the site and FTP credentials are required when uploading a new theme or plugin, then this technically allows an RCE when the user would otherwise have no means of executing arbitrary PHP code. This issue only affects Administrator level users on single site installations, and Super Admin level users on Multisite installations where it's otherwise expected that the user does not have permission to upload or execute arbitrary PHP code. Lower level users are not affected. Sites where the DISALLOWFILEMODS constant is set to true are not affected. Sites where an administrative user either does not need to enter FTP credentials or they have access to the valid FTP credentials, are not affected. The issue was fixed in WordPress 6.4.3 on January 30, 2024 and backported to versions 6.3.3, 6.2.4, 6.1.5, 6.0.7, 5.9.9, 5.8.9, 5.7.11, 5.6.13, 5.5.14, 5.4.15, 5.3.17, 5.2.20, 5.1.18, 5.0.21, 4.9.25, 2.8.24, 4.7.28, 4.6.28, 4.5.31, 4.4.32, 4.3.33, 4.2.37, and 4.1.40. A workaround is available. If the DISALLOWFILEMODS constant is defined as true then it will not be possible for any user to upload a plugin and therefore this issue will not be exploitable.

Affected Software

1 affected component

WordPress WordPress<6.4.3, >=6.3.0<6.3.3, >=6.2.0<6.2.4, >=6.1.0<6.1.5, >=6.0.0<6.0.7, >=5.9.0<5.9.9, >=5.8.0<5.8.9, >=5.7.0<5.7.11, >=5.6.0<5.6.13, >=5.5.0<5.5.14, >=5.4.0<5.4.15, >=5.3.0<5.3.17, >=5.2.0<5.2.20, >=5.1.0<5.1.18, >=5.0.0<5.0.21, >=4.9.0<4.9.25, >=4.7.0<4.7.28, >=4.6.0<4.6.28, >=4.5.0<4.5.31, >=4.4.0<4.4.32, >=4.3.0<4.3.33, >=4.2.0<4.2.37, >=4.1.0<4.1.40, >=2.8.0<2.8.24

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 6.4.3
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 6.3.3
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 6.2.4
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 6.1.5
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 6.0.7
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.9.9
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.8.9
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.7.11
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.6.13
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.5.14
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.4.15
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.3.17
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.2.20
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.1.18
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 5.0.21
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.9.25
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 2.8.24
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.7.28
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.6.28
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.5.31
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.4.32
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.3.33
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.2.37
Upgrade
Upgrade WordPress to a version that resolves this vulnerability.
Fixed in 4.1.40
Configuration
Define the DISALLOW_FILE_MODS constant as true to prevent users from uploading plugins.
WordPress DISALLOW_FILE_MODS = true

Event History

Apr 4, 2024

CVE Published

via OSV·10:59 PM

Data Sourced

via OSV·10:59 PM

DescriptionSeverityWeakness

Frequently Asked Questions

Which users and deployment types are affected?

The issue affects Administrator users on single-site installations and Super Admin users on Multisite installations. Lower-privileged users are not affected.

What conditions are required for exploitation?

An affected administrative user must upload a non-ZIP file through the plugin installer, and WordPress must request FTP credentials to move the file outside the uploads directory. The RCE scenario additionally requires DISALLOW_FILE_EDIT to be set to true, where the user otherwise cannot execute arbitrary PHP code.

Are default file-modification configurations affected?

Sites with DISALLOW_FILE_MODS set to true are not affected. Sites are also not affected when the administrative user does not need to provide FTP credentials or has access to valid FTP credentials.

What can be done if patching is not immediately possible?

Set DISALLOW_FILE_MODS to true to prevent the affected file-modification path. Also avoid configurations that require administrators to enter FTP credentials for theme or plugin uploads.

BIT-wordpress-multisite-2024-31210: PHP file upload bypass via Plugin installer

Affected Software

Remediation

Event History

Frequently Asked Questions

Which users and deployment types are affected?

What conditions are required for exploitation?

Are default file-modification configurations affected?

What can be done if patching is not immediately possible?

Company

Resources

Contact

Frequently Asked Questions

Which users and deployment types are affected?

What conditions are required for exploitation?

Are default file-modification configurations affected?

What can be done if patching is not immediately possible?