Custom CSS injection via missing nonce validation
Published Feb 21, 2025 · Updated Apr 8, 2026
CSRF in Victor Freitas WPUpper Share Buttons 3.51 and earlier allows remote attackers to inject custom CSS through a forged request. The save_custom_css_request AJAX handler accepts attacker-supplied CSS without verifying a WordPress nonce that binds the request to the administrator's session. Exploitation requires a logged-in site administrator to follow an attacker-controlled link or perform an equivalent forged action, after which the site's presentation can be altered.
Summary
What happened
CSRF in Victor Freitas WPUpper Share Buttons 3.51 and earlier allows remote attackers to inject custom CSS through a forged request. The save_custom_css_request AJAX handler accepts attacker-supplied CSS without verifying a WordPress nonce that binds the request to the administrator's session. Exploitation requires a logged-in site administrator to follow an attacker-controlled link or perform an equivalent forged action, after which the site's presentation can be altered.
The record
- CVE
- CVE-2024-13883
- Published
- Feb 21, 2025
- Updated
- Apr 8, 2026
- Vendor
- Freitas Victor
- Product
- WPUpper Share Buttons
- Classifications
- CWE-352, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 21, 2025CVE publishedPublication date reported by the CVE source.
- Apr 8, 2026Record 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.
- Affected versionversion=0 <=3.51
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
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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