CVE-2025-7100 is a critical vulnerability identified in BoyunCMS versions up to 1.4.20. The issue resides in the file /application/user/controller/Index.php, specifically involving the manipulation of the 'image' argument, which leads to an unrestricted file upload vulnerability. This vulnerability allows an unauthenticated remote attacker to upload arbitrary files to the server without proper validation or restrictions. The vulnerability does not require user interaction or authentication, making it remotely exploitable over the network. The CVSS 4.0 score is 5.3 (medium severity), reflecting the moderate impact and ease of exploitation, but with some limitations on the scope and impact on confidentiality, integrity, and availability. The unrestricted upload flaw can be leveraged to upload malicious scripts or web shells, potentially leading to remote code execution, server compromise, data theft, or pivoting within the affected environment. Although no known exploits are currently reported in the wild, the public disclosure of the exploit increases the risk of exploitation. The vulnerability affects all BoyunCMS versions from 1.4.0 through 1.4.20, indicating a wide range of affected deployments. The lack of patch links suggests that no official fix has been released at the time of publication, increasing the urgency for mitigation.

For European organizations using BoyunCMS, this vulnerability poses a significant risk. Successful exploitation could lead to unauthorized access, data breaches, defacement of websites, or use of compromised servers as launchpads for further attacks. Organizations in sectors such as government, finance, healthcare, and e-commerce, which may rely on BoyunCMS for content management, could face operational disruptions and reputational damage. The ability to upload arbitrary files remotely without authentication increases the likelihood of automated attacks and widespread compromise. Additionally, the vulnerability could be exploited to deploy ransomware or other malware, impacting data availability and integrity. Given the public disclosure and lack of patches, European entities must prioritize risk assessment and mitigation to prevent exploitation.

1. Immediate mitigation should include restricting or disabling file upload functionality in BoyunCMS until a patch is available. 2. Implement web application firewall (WAF) rules to detect and block suspicious file upload attempts targeting the vulnerable endpoint (/application/user/controller/Index.php). 3. Employ strict input validation and file type verification at the server level to prevent unauthorized file types from being uploaded. 4. Monitor server logs for unusual activity related to file uploads or access to the vulnerable controller. 5. Isolate affected systems and conduct thorough security audits to detect any signs of compromise. 6. If possible, upgrade to a newer version of BoyunCMS once an official patch or fix is released. 7. Use network segmentation to limit the impact of a potential compromise. 8. Educate administrators about the risk and encourage immediate application of any vendor advisories or community patches.