CVE-2025-9899 is a Cross-Site Request Forgery (CSRF) vulnerability identified in the Trust Reviews plugin for WordPress, which integrates review feeds from platforms such as Google, Tripadvisor, Yelp, and Airbnb. The vulnerability affects all versions up to and including version 1.0 of the plugin. The root cause is the absence or improper implementation of nonce validation in the feed_save function, a security mechanism designed to verify the legitimacy of requests. This flaw allows an unauthenticated attacker to craft malicious requests that, if executed by a site administrator (e.g., by clicking a link), can create or modify feed entries without proper authorization. The vulnerability does not require the attacker to have privileges or prior authentication but does require user interaction from an administrator, making it a targeted attack vector. The CVSS v3.1 base score is 6.1, reflecting a medium severity level, with an attack vector of network (remote), low attack complexity, no privileges required, but requiring user interaction. The impact scope is changed (S:C), indicating that the vulnerability affects resources beyond the vulnerable component. The confidentiality and integrity impacts are low, as the attacker can manipulate review feed data but cannot directly compromise system availability or escalate privileges. No known exploits are reported in the wild as of the publication date (September 27, 2025). The vulnerability is classified under CWE-352, which corresponds to CSRF attacks that exploit missing or incorrect anti-CSRF tokens.

For European organizations using WordPress websites with the Trust Reviews plugin, this vulnerability poses a risk of unauthorized modification or creation of review feed entries. Such manipulation can undermine the integrity of displayed customer reviews, potentially damaging brand reputation and customer trust. Attackers could use this to insert misleading or fraudulent reviews, impacting consumer decisions and business credibility. While the vulnerability does not directly compromise system availability or allow privilege escalation, the integrity breach can have significant indirect effects, especially for e-commerce, hospitality, and service sectors relying heavily on online reviews. Additionally, regulatory compliance under GDPR may be implicated if manipulated content leads to misinformation or impacts consumer rights. The requirement for administrator interaction means that organizations with less security-aware staff are at higher risk. Given the widespread use of WordPress in Europe and the popularity of review aggregation plugins, the threat surface is considerable. However, the absence of known exploits and the medium severity score suggest a moderate but actionable risk.

To mitigate this vulnerability, European organizations should immediately audit their WordPress installations for the presence of the Trust Reviews plugin and verify the plugin version. Since no patch links are currently available, administrators should consider temporarily disabling the plugin until a secure update is released. Implementing strict administrative access controls and training administrators to recognize and avoid suspicious links can reduce the risk of successful CSRF attacks. Additionally, organizations should monitor web server logs for unusual POST requests targeting the feed_save function or unexpected changes in review content. Employing Web Application Firewalls (WAFs) with custom rules to detect and block CSRF attack patterns can provide an additional layer of defense. Once a patched version is released, prompt updating is critical. Developers maintaining the plugin should implement proper nonce validation and CSRF tokens in all state-changing requests. Finally, organizations should consider isolating administrative interfaces behind VPNs or IP whitelisting to limit exposure.