CVE-2025-53560: Noisa Object Injection Vulnerability

CVE-2025-53560 Overview

CVE-2025-53560 is a PHP Object Injection vulnerability in the Noisa WordPress theme developed by rascals. The flaw stems from insecure deserialization of untrusted data [CWE-502] and affects all versions of Noisa up to and including 2.6.0. An authenticated attacker with low privileges can inject crafted serialized PHP objects to trigger unsafe magic methods within the theme or other loaded plugins. Successful exploitation can lead to arbitrary code execution, data tampering, or full site compromise depending on the available gadget chains. The vulnerability is exploitable over the network and requires no user interaction.

Critical Impact
Authenticated attackers can inject PHP objects to achieve code execution, data manipulation, or denial of service on WordPress sites running vulnerable Noisa theme versions.

Affected Products

rascals Noisa WordPress theme — versions up to and including 2.6.0
WordPress sites using the Noisa theme alongside plugins exposing exploitable gadget chains
Hosting environments where vulnerable Noisa installations are deployed

Discovery Timeline

2025-08-20 - CVE-2025-53560 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-53560

Vulnerability Analysis

The vulnerability arises from the theme passing attacker-controlled input to PHP's unserialize() function without validation. When PHP deserializes a crafted payload, it instantiates objects and triggers magic methods such as __wakeup(), __destruct(), or __toString(). Attackers chain these methods together using available classes in the WordPress runtime to build POP (Property-Oriented Programming) chains.

The issue is classified under CWE-502 (Deserialization of Untrusted Data). Exploitation requires authenticated access at the contributor level or higher, but the attacker does not need administrative privileges. The impact ranges from arbitrary file read and write to remote code execution when suitable gadget chains exist in installed plugins.

Root Cause

The Noisa theme accepts serialized data from user-controllable sources such as request parameters, options, or cookies and deserializes it without integrity checks or type filtering. PHP's unserialize() reconstructs objects from this stream, allowing an attacker to influence object state and class selection.

Attack Vector

An authenticated attacker submits a crafted serialized payload to a vulnerable endpoint exposed by the Noisa theme. The payload references classes whose magic methods perform sensitive operations such as file writes, SQL queries, or system calls. WordPress sites with common plugins frequently expose viable gadget chains that escalate object injection into remote code execution.

For technical details and proof-of-concept information, refer to the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2025-53560

Indicators of Compromise

HTTP requests containing serialized PHP payloads with patterns like O: (object), a: (array), or s: (string) followed by length specifiers
Unexpected file modifications in the WordPress wp-content/themes/noisa/ directory or arbitrary write locations
New administrator accounts, scheduled tasks, or unknown PHP files created in the web root
Outbound network connections from the PHP worker process to unfamiliar hosts

Detection Strategies

Inspect web server access logs for POST requests containing serialized object signatures sent to Noisa theme endpoints
Correlate authenticated low-privilege user activity with theme-handled requests that contain unserialize-style payloads
Monitor PHP error logs for warnings tied to unknown class instantiation or magic method execution

Monitoring Recommendations

Enable file integrity monitoring on theme, plugin, and wp-config.php files to detect tampering
Forward WordPress audit logs and web server telemetry into a centralized analytics platform for correlation
Alert on creation of administrator accounts, modification of user roles, and changes to the WordPress options table outside normal change windows

How to Mitigate CVE-2025-53560

Immediate Actions Required

Identify all WordPress instances running the Noisa theme version 2.6.0 or earlier and prioritize them for remediation
Restrict contributor and author-level account creation until a patched version is deployed
Place the affected sites behind a web application firewall with rules blocking serialized PHP payloads in request parameters
Rotate WordPress secret keys in wp-config.php and force password resets for privileged users

Patch Information

At the time of publication, the Patchstack advisory lists Noisa versions through 2.6.0 as affected. Site administrators should consult the vendor and the Patchstack advisory for the latest fixed version and apply updates as soon as they are available.

Workarounds

Temporarily switch to an alternate theme until a patched Noisa release is installed
Limit theme-handled endpoints with server-level access controls or authentication rules
Deploy WAF signatures that detect and block serialized PHP object patterns in HTTP requests
Remove or disable optional Noisa features that accept serialized input where feasible

bash

# Example ModSecurity rule to block serialized PHP object payloads
SecRule ARGS "@rx (?:^|[^a-zA-Z0-9_])O:[0-9]+:\"[a-zA-Z_][a-zA-Z0-9_]*\":[0-9]+:\{" \
    "id:1005356,phase:2,deny,status:403,log,\
    msg:'Possible PHP Object Injection attempt (CVE-2025-53560)'"