CVE-2025-8999
📋 TL;DR
The Sydney WordPress theme has a missing capability check in the 'activate_modules' function, allowing authenticated users with Subscriber-level access or higher to activate or deactivate theme modules without proper authorization. This affects all versions up to and including 2.56. Attackers can modify theme functionality and potentially disrupt site operations.
💻 Affected Systems
- Sydney WordPress Theme
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers could disable critical theme modules (like security features or site functionality), causing site disruption, or enable malicious modules that introduce backdoors or other vulnerabilities.
Likely Case
Attackers with low-privilege accounts could tamper with theme settings, potentially breaking site appearance or functionality, or enabling modules that expose additional attack surfaces.
If Mitigated
With proper user access controls and monitoring, impact is limited to minor configuration changes that can be reverted, though it still represents an integrity violation.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once an attacker has valid credentials. No special tools needed beyond web access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 2.57 or later
Vendor Advisory: https://themes.trac.wordpress.org/changeset/288374/
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Appearance > Themes. 3. Find Sydney theme and check for updates. 4. If update available, click 'Update Now'. 5. Alternatively, manually download version 2.57+ from WordPress.org and replace theme files.
🔧 Temporary Workarounds
Remove vulnerable function via child theme
allOverride the vulnerable function in a child theme to add proper capability checks or disable the functionality entirely.
Create a child theme with modified class-sydney-modules.php file that adds capability checks to activate_modules function
Restrict user roles
allTemporarily limit user accounts to only trusted administrators until patching is complete.
Use WordPress user management to review and restrict accounts with Subscriber or higher roles
🧯 If You Can't Patch
- Implement strict user access controls and review all user accounts with Subscriber or higher privileges
- Monitor theme module changes and user activity logs for suspicious modifications
🔍 How to Verify
Check if Vulnerable:
Check Sydney theme version in WordPress admin under Appearance > Themes. If version is 2.56 or lower, the system is vulnerable.Check Version:
In WordPress admin: Appearance > Themes, or check wp-content/themes/sydney/style.css for Version: headerVerify Fix Applied:
After updating, verify theme version shows 2.57 or higher. Test that only administrators can modify theme modules.📡 Detection & Monitoring
Log Indicators:
- WordPress audit logs showing non-admin users activating/deactivating theme modules
- Unexpected changes to theme settings or module status
Network Indicators:
- POST requests to theme module activation endpoints from non-admin user accounts
SIEM Query:
source="wordpress" AND (event="theme_module_activation" OR event="theme_module_deactivation") AND user_role!="administrator"🔗 References
- https://themes.trac.wordpress.org/browser/sydney/2.55/inc/classes/class-sydney-modules.php#L166
- https://themes.trac.wordpress.org/browser/sydney/2.55/inc/modules/class-sydney-modules.php#L72
- https://themes.trac.wordpress.org/changeset/288374/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/965582c6-a52e-4f88-81ef-b5dd761a0c23?source=cve
