The vulnerability identified as CVE-2024-12314 affects the Rapid Cache plugin for WordPress, developed by megaoptim, in all versions up to 1.2.3. The core issue arises from the plugin's practice of storing HTTP headers within cached data without proper sanitization or validation. This design flaw enables unauthenticated attackers to perform cache poisoning by injecting custom HTTP headers into the cache. Because these headers are stored and served to subsequent users, malicious payloads embedded in headers can trigger Cross-Site Scripting (XSS) attacks. The vulnerability is classified under CWE-524, which pertains to the use of caches containing sensitive information. The CVSS v3.1 base score is 7.2, indicating high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and a scope change (S:C). The impact affects confidentiality and integrity but not availability. The vulnerability allows attackers to compromise the integrity of cached content, potentially leading to theft of sensitive information or session hijacking via XSS. No patches or fixes are currently linked, and no exploits have been observed in the wild as of the publication date. The vulnerability is particularly concerning for websites relying on the Rapid Cache plugin for performance optimization, as it undermines the trustworthiness of cached content delivered to users.

This vulnerability poses significant risks to organizations running WordPress sites with the Rapid Cache plugin. Successful exploitation can lead to Cross-Site Scripting attacks, which may allow attackers to steal user credentials, hijack sessions, or deliver malicious scripts to site visitors. Since the attack requires no authentication and can be executed remotely, the threat surface is broad. The integrity of cached content is compromised, potentially affecting multiple users simultaneously. Confidential information leakage is possible if sensitive headers or data are exposed or manipulated. Although availability is not directly impacted, the reputational damage and potential regulatory consequences from data breaches or user compromise can be severe. Organizations relying on this plugin for caching may experience increased risk of targeted attacks, especially if they have high traffic or handle sensitive user data. The lack of known exploits in the wild suggests a window of opportunity for proactive mitigation before widespread exploitation occurs.

Immediate mitigation should focus on disabling or uninstalling the Rapid Cache plugin until a secure patched version is released. If disabling the plugin is not feasible, organizations should implement web application firewall (WAF) rules to detect and block suspicious HTTP headers that could be used for cache poisoning. Input validation and sanitization mechanisms should be enforced at the web server or application level to prevent injection of malicious headers. Monitoring cache behavior and logs for unusual header patterns can help detect attempted exploitation. Site administrators should ensure all WordPress components, including plugins, are regularly updated and subscribe to security advisories from megaoptim and WordPress security communities. Additionally, employing Content Security Policy (CSP) headers can mitigate the impact of XSS attacks by restricting script execution. Finally, segregating cache storage or using cache mechanisms that do not store HTTP headers can reduce exposure to this vulnerability.