CVE-2024-24926 Overview
CVE-2024-24926 is a deserialization of untrusted data vulnerability [CWE-502] in the UnitedThemes Brooklyn WordPress theme. The flaw affects all versions up to and including 4.9.7.6. An authenticated attacker with low privileges can inject malicious PHP objects through unsafe deserialization. Successful exploitation leads to remote code execution, arbitrary file operations, or full site compromise.
Brooklyn is a widely deployed commercial multi-purpose theme, expanding the potential attack surface across many WordPress sites.
Critical Impact
Authenticated attackers can trigger PHP Object Injection to achieve remote code execution, resulting in high impact to confidentiality, integrity, and availability of affected WordPress sites.
Affected Products
- UnitedThemes Brooklyn WordPress Theme versions up to and including 4.9.7.6
- WordPress sites bundling the Brooklyn theme with vulnerable dependencies
- Deployments where the theme is active or its PHP files are reachable
Discovery Timeline
- 2024-02-12 - CVE-2024-24926 published to the National Vulnerability Database
- 2026-06-17 - Last updated in the NVD database
Technical Details for CVE-2024-24926
Vulnerability Analysis
The vulnerability is a PHP Object Injection issue rooted in unsafe deserialization of attacker-controlled input. When user-supplied data reaches a PHP unserialize() call without validation, the interpreter reconstructs arbitrary PHP objects. This triggers magic methods such as __wakeup(), __destruct(), or __toString() on classes present in the runtime.
Attackers chain these magic methods across loaded classes to build POP (Property-Oriented Programming) gadgets. The resulting gadget chain can execute arbitrary code, write files, or manipulate the WordPress database. Because WordPress plugins and themes commonly share the runtime, the pool of usable gadgets is large.
Exploitation requires low-privilege authentication, which reduces the barrier for subscribers, contributors, or compromised low-tier accounts. The attack traverses the network with low complexity and no user interaction, producing full compromise of the site process.
Root Cause
The root cause is invocation of PHP deserialization routines on data derived from HTTP requests, cookies, or stored options without integrity verification. Brooklyn passes untrusted input into unserialize() where a signed or JSON-based alternative should be used. Refer to the Patchstack Vulnerability Report for the affected code paths.
Attack Vector
An authenticated attacker submits a crafted serialized payload to a vulnerable theme endpoint over HTTP. The payload instantiates chosen classes whose magic methods produce side effects such as file writes or command execution. No user interaction is required beyond the attacker's own authenticated request.
No public proof-of-concept exploit code has been released. See the Patchstack Vulnerability Report for advisory-level detail.
Detection Methods for CVE-2024-24926
Indicators of Compromise
- HTTP POST or GET requests to Brooklyn theme endpoints containing serialized PHP markers such as O:, a:, or s: in parameter values.
- Unexpected PHP files or webshells created within wp-content/themes/brooklyn/ or wp-content/uploads/.
- New or modified WordPress administrator accounts and unexpected changes to the wp_options table.
- Outbound network connections from the PHP worker to attacker-controlled infrastructure shortly after theme requests.
Detection Strategies
- Inspect web server and WAF logs for request bodies containing PHP serialization tokens sent to theme URLs.
- Monitor file integrity across the theme directory and the WordPress core to detect unauthorized modifications.
- Alert on PHP processes spawning shell interpreters such as sh, bash, or cmd.exe, which indicate object injection reaching command execution.
Monitoring Recommendations
- Enable verbose WordPress and PHP error logging to capture unserialize warnings and class instantiation errors.
- Forward web server, WAF, and endpoint telemetry to a centralized platform for correlation and long-term retention.
- Baseline normal administrative activity and alert on anomalous authenticated requests to theme scripts.
How to Mitigate CVE-2024-24926
Immediate Actions Required
- Update the Brooklyn theme to a version later than 4.9.7.6 as published by UnitedThemes.
- Audit all WordPress user accounts and remove or reset any unnecessary low-privilege users that could be leveraged for authenticated exploitation.
- Review the theme directory and wp-content/uploads/ for recently modified PHP files and remove any unauthorized artifacts.
- Rotate WordPress secret keys in wp-config.php and invalidate active sessions after remediation.
Patch Information
UnitedThemes has addressed the vulnerability in versions above 4.9.7.6. Consult the Patchstack Vulnerability Report and the vendor's changelog for the specific fixed release and upgrade guidance.
Workarounds
- Deploy a WordPress-aware WAF ruleset that blocks requests containing serialized PHP payloads targeting theme endpoints.
- Restrict access to wp-admin and authenticated theme endpoints using IP allowlists or reverse-proxy authentication where feasible.
- Disable or replace the Brooklyn theme with a maintained alternative until patching is complete.
# Example: block requests containing PHP serialized objects in ModSecurity
SecRule ARGS "@rx (?:^|[&=])[Oa]:\d+:\"" \
"id:1002401,phase:2,deny,status:403,\
msg:'Possible PHP Object Injection payload (CVE-2024-24926)'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
