CVE-2022-39977 is a high-severity arbitrary file upload vulnerability identified in the Online Pet Shop Web Application version 1.0. The vulnerability exists in the Editing function of the User module, where the application fails to properly validate or restrict the type of files uploaded through the picture upload interface. This flaw allows an attacker with high privileges (as indicated by the CVSS vector requiring PR:H) to upload crafted PHP files, which can then be executed on the server. Successful exploitation leads to remote code execution (RCE), compromising the confidentiality, integrity, and availability of the affected system. The vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type), highlighting the lack of proper input validation and sanitization controls. The CVSS v3.1 score of 7.2 reflects the network attack vector, low attack complexity, and no user interaction required, but with the prerequisite of elevated privileges. No patches or vendor information are currently available, and no known exploits have been reported in the wild as of the publication date.

For European organizations, this vulnerability poses a significant risk, especially for businesses running the affected Online Pet Shop Web App or similar custom e-commerce platforms with comparable upload functionalities. Exploitation could lead to full system compromise, data breaches involving customer personal and payment information, defacement of web assets, and potential lateral movement within corporate networks. Given the e-commerce context, the impact extends to financial losses, reputational damage, and regulatory penalties under GDPR for failure to protect personal data. The requirement for high privileges limits the attack surface to insiders or attackers who have already compromised user accounts with elevated rights, but once exploited, the attacker gains substantial control. This threat is particularly concerning for SMEs and online retailers in Europe that may use less mature or custom-developed web applications without robust security controls.

Organizations should immediately audit their web applications for unrestricted file upload functionalities, especially in user profile or content editing modules. Specific mitigations include implementing strict server-side validation of uploaded files, enforcing allowlists for file types (e.g., only images with validated MIME types and extensions), and scanning uploaded files for malicious content. Disabling execution permissions on upload directories is critical to prevent execution of uploaded scripts. Employing web application firewalls (WAFs) with rules to detect and block suspicious file uploads can provide an additional layer of defense. Since no official patches are available, organizations should consider isolating or disabling the vulnerable upload feature until a fix is released. Regular privilege audits to minimize users with high-level access reduce the risk of exploitation. Monitoring logs for unusual upload activity and conducting penetration testing focused on file upload vectors are also recommended.