The vulnerability identified as CVE-2025-12677 affects the KiotViet Sync plugin for WordPress, specifically all versions up to and including 1.8.5. The flaw resides in the register_api_route() function within the kiotvietsync/includes/public_actions/WebHookAction.php file. This function improperly exposes the webhook token value, a sensitive credential used to authenticate webhook requests, to unauthenticated attackers. Because the API route does not enforce authentication or authorization checks, any remote attacker can retrieve the webhook token simply by accessing the vulnerable endpoint. The exposure of this token (classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) can enable attackers to impersonate legitimate webhook calls, potentially triggering unauthorized actions or data exfiltration through the webhook mechanism. The vulnerability has a CVSS 3.1 base score of 5.3, reflecting a medium severity level due to its network attack vector, lack of required privileges or user interaction, and limited impact confined to confidentiality. No known exploits have been reported in the wild as of the publication date (November 5, 2025). However, the risk remains significant for organizations relying on this plugin for integrating their WordPress sites with KiotViet services, especially in e-commerce contexts where webhook tokens are critical for operational workflows.

The primary impact of CVE-2025-12677 is the unauthorized disclosure of webhook tokens, which compromises the confidentiality of sensitive authentication credentials. Attackers who obtain these tokens can potentially forge webhook requests, leading to unauthorized triggering of backend processes, data leakage, or manipulation of business logic tied to webhook events. Although the vulnerability does not directly affect system integrity or availability, the misuse of exposed tokens can result in indirect integrity violations or operational disruptions. Organizations using the KiotViet Sync plugin may face risks including fraudulent transactions, data inconsistencies, or unauthorized access to integrated services. The medium CVSS score reflects that while exploitation is straightforward due to no authentication requirements, the scope of impact is limited to the confidentiality of webhook tokens. The absence of known exploits in the wild reduces immediate threat urgency but does not eliminate the risk of future exploitation. Given the widespread use of WordPress and the plugin's role in e-commerce synchronization, affected organizations worldwide could experience reputational damage, financial losses, and compliance issues if the vulnerability is exploited.

To mitigate CVE-2025-12677, organizations should take the following specific actions: 1) Immediately restrict access to the vulnerable API route by implementing authentication and authorization controls, such as requiring valid user credentials or IP whitelisting, to prevent unauthenticated access to webhook tokens. 2) Rotate all webhook tokens associated with the KiotViet Sync plugin to invalidate any potentially exposed credentials. 3) Monitor logs and network traffic for unusual or unauthorized webhook activity that could indicate exploitation attempts. 4) If available, update the KiotViet Sync plugin to a patched version once released by the vendor; in the absence of a patch, consider disabling the plugin or the webhook functionality temporarily to prevent token leakage. 5) Employ Web Application Firewalls (WAFs) to detect and block suspicious requests targeting the vulnerable endpoint. 6) Conduct a security review of other API routes and plugin components to identify and remediate similar exposure risks. 7) Educate development and operations teams about secure API design principles to avoid future sensitive information exposure.