CVE-2024-13556 is a vulnerability classified under CWE-862 (Missing Authorization) found in the Affiliate Links: WordPress Plugin for Link Cloaking and Link Management by wecantrack. The flaw exists in all versions up to and including 3.0.1 and allows unauthenticated attackers to perform PHP Object Injection through deserialization of untrusted input during the file export functionality. Deserialization vulnerabilities occur when untrusted data is processed by PHP's unserialize function, potentially allowing attackers to inject crafted objects. However, this vulnerability's impact depends on the presence of a POP (Property Oriented Programming) chain in other installed plugins or themes, which can be leveraged to perform malicious actions such as arbitrary file deletion, data exfiltration, or remote code execution. The plugin itself does not contain a POP chain, so the vulnerability is a prerequisite condition that requires a secondary gadget chain to be fully exploitable. The vulnerability is remotely exploitable without authentication or user interaction, but the attack complexity is high due to the need for a suitable POP chain. The CVSS v3.1 score of 8.1 reflects high confidentiality, integrity, and availability impacts if exploited. No patches or fixes have been linked yet, and no known exploits are reported in the wild. This vulnerability highlights the risks of insecure deserialization combined with missing authorization checks in WordPress plugins, especially in complex plugin/theme environments.

If exploited, this vulnerability could have severe consequences for affected WordPress sites. Attackers could gain the ability to execute arbitrary PHP code, delete critical files, or access sensitive data stored on the server. This could lead to website defacement, data breaches, or complete site takeover. The requirement for a POP chain means exploitation is conditional but still poses a significant risk in environments with multiple plugins or themes installed, which is common in WordPress deployments. The vulnerability affects the confidentiality, integrity, and availability of the affected systems. For organizations relying on this plugin for affiliate link management, a successful attack could disrupt marketing operations, damage reputation, and lead to financial losses. Additionally, compromised WordPress sites could be used as a pivot point for further attacks within an organization's network or to distribute malware to visitors.

1. Immediately update the Affiliate Links plugin to a patched version once available from the vendor. Monitor vendor communications for official patches. 2. In the interim, disable the file export functionality or restrict access to it via web application firewall (WAF) rules or server-level access controls to prevent unauthenticated access. 3. Audit installed plugins and themes for known POP chains or gadget chains that could be leveraged in conjunction with this vulnerability and consider removing or updating them. 4. Implement strict input validation and sanitization on any user-controllable inputs related to plugin functionality. 5. Employ security plugins that detect and block deserialization attacks and anomalous PHP object injection attempts. 6. Regularly back up WordPress sites and maintain offline copies to enable recovery in case of compromise. 7. Monitor logs for suspicious activity related to file exports or unusual PHP object deserialization attempts. 8. Harden the WordPress environment by following the principle of least privilege for file permissions and user roles to limit potential damage from exploitation.