CVE-2025-63710 identifies a Cross-Site Request Forgery (CSRF) vulnerability in the send_message.php endpoint of SourceCodester Simple Public Chat Room version 1.0. The core issue arises because the application fails to implement standard CSRF protections, such as anti-CSRF tokens, nonces, or same-site cookie restrictions. This absence allows an attacker to craft a malicious HTML page that, when visited by an authenticated user, automatically submits a forged POST request to the vulnerable endpoint. Since the request is executed with the victim's session privileges, the attacker can perform unauthorized actions, specifically sending arbitrary messages in any chat room. This can lead to message spoofing, misinformation, or disruption of chat communications. The vulnerability is remotely exploitable over the network without requiring prior authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The CVSS score of 6.5 reflects a medium severity, primarily due to the impact on confidentiality and integrity, while availability remains unaffected. No patches or known exploits are currently documented, emphasizing the need for proactive mitigation. The vulnerability is classified under CWE-352, which covers CSRF weaknesses. Given the nature of the chat application, exploitation could facilitate social engineering, phishing, or reputational damage within organizations relying on this software for communication.

For European organizations using SourceCodester Simple Public Chat Room 1.0, this vulnerability can undermine trust in internal and external communications by allowing attackers to send unauthorized messages impersonating legitimate users. This can lead to misinformation, social engineering attacks, or disruption of collaborative workflows. Confidentiality is impacted as attackers can manipulate message content, potentially leaking sensitive information through crafted responses or by inducing users to reveal data. Integrity is compromised by unauthorized message injection, which can distort communication records. Although availability is not directly affected, the reputational damage and potential regulatory scrutiny under GDPR for failing to secure communication platforms could have significant operational and financial consequences. Organizations in sectors such as finance, government, and critical infrastructure that rely on secure chat communications are particularly at risk. The lack of known exploits currently reduces immediate risk but does not diminish the urgency for remediation, as attackers could develop exploits rapidly once the vulnerability is public.

To mitigate CVE-2025-63710, organizations should implement robust CSRF protections in the SourceCodester Simple Public Chat Room application. This includes integrating anti-CSRF tokens or nonces in all state-changing requests, especially POST requests to send_message.php. Enforcing the SameSite attribute on session cookies (preferably 'Strict' or 'Lax') will help prevent cookies from being sent with cross-site requests. Validating the Origin and Referer headers on incoming requests can provide additional verification that requests originate from trusted sources. If possible, upgrading to a patched version of the software or applying vendor-provided fixes is recommended once available. In the interim, restricting access to the chat application via network segmentation or VPNs can reduce exposure. User education to avoid clicking suspicious links and monitoring chat logs for unusual message patterns can help detect exploitation attempts. Implementing Content Security Policy (CSP) headers may also reduce the risk of malicious script execution that could facilitate CSRF attacks.