CVE-2025-12331 identifies a vulnerability in Willow CMS versions 1.0 through 1.4.0 affecting the /admin/images/add functionality. The vulnerability allows an attacker with high-level privileges to perform unrestricted file uploads without adequate validation or sanitization. This flaw arises from insufficient checks on the uploaded file type, size, or content, enabling potentially malicious files such as web shells or scripts to be placed on the server. Since the upload endpoint is accessible remotely, an attacker can exploit this vulnerability over the network. However, exploitation requires the attacker to have authenticated access with elevated privileges, limiting the attack surface to insiders or compromised accounts. The vulnerability impacts the confidentiality, integrity, and availability of the affected system by allowing arbitrary code execution, data manipulation, or service disruption. Although no active exploitation in the wild has been reported, the public availability of exploit code increases the likelihood of attacks. The CVSS 4.0 base score of 5.1 reflects a medium severity, considering the ease of network access but the requirement for high privileges and no user interaction. Willow CMS is a content management system used by various organizations for website and content management, making this vulnerability relevant for entities relying on it for their web infrastructure.

For European organizations, this vulnerability poses a risk of unauthorized file uploads leading to server compromise, data breaches, or website defacement. Organizations using Willow CMS for public-facing websites or internal portals could see disruption of services or leakage of sensitive information. Attackers exploiting this flaw could deploy web shells to maintain persistent access or pivot within the network. The requirement for high privileges means that insider threats or compromised administrator accounts are the most likely vectors. The impact on confidentiality, integrity, and availability could be significant if exploited, especially in sectors like government, finance, or critical infrastructure where web presence is crucial. Additionally, reputational damage and regulatory consequences under GDPR could arise from breaches facilitated by this vulnerability. The public availability of exploit code increases the urgency for European organizations to address this issue promptly.

1. Immediately restrict access to the /admin/images/add endpoint to only trusted administrators and limit the number of users with high privileges. 2. Implement strict server-side validation of uploaded files, including file type, size, and content inspection to prevent malicious files. 3. Employ web application firewalls (WAFs) with rules designed to detect and block suspicious upload attempts targeting this endpoint. 4. Monitor logs for unusual upload activity or access patterns to detect potential exploitation attempts early. 5. If possible, upgrade to a patched version of Willow CMS once available or apply vendor-provided patches promptly. 6. Use network segmentation to isolate CMS servers from critical internal systems to limit lateral movement in case of compromise. 7. Enforce multi-factor authentication (MFA) for administrative accounts to reduce the risk of credential compromise. 8. Conduct regular security audits and penetration testing focused on file upload functionalities. 9. Educate administrators on the risks of privilege misuse and encourage strong password hygiene. 10. Backup website data and configurations regularly to enable rapid recovery if exploitation occurs.