CVE-2026-86666 in iWebShop-5
Summary
by MITRE • 09/08/2026
A security flaw has been discovered in aircheng-org iWebShop-5 up to 5.15. Impacted is the function upload_json/uploadFile of the file controllers/pic.php. The manipulation results in unrestricted upload. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified within aircheng-org iWebShop versions up to 5.15 represents a critical security deficiency located in the file upload functionality, specifically affecting the upload_json and uploadFile functions found in controllers/pic.php. This flaw is classified as an unrestricted file upload vulnerability, which falls under CWE-434 in the Common Weakness Enumeration standard. The core technical issue stems from insufficient validation of uploaded files by the application's backend logic. When a user interacts with these endpoints to submit images or other media assets for storage on the server, the system fails to adequately verify the file type, content integrity, and extension against an allowlist. This lack of rigorous input sanitization allows attackers to bypass standard security controls that are typically designed to prevent malicious code execution through uploaded files.
The operational impact of this vulnerability is severe due to its remote executability. An attacker can leverage this flaw from a distant location without requiring prior authentication or user interaction, provided the target application exposes these endpoints publicly. By crafting a specially formatted HTTP request containing a malicious payload disguised as an image file, such as a PHP script with embedded web shell code, the attacker can trick the server into saving and executing arbitrary commands. This capability effectively grants the adversary unauthorized access to the underlying operating system or web server environment. Once executed, this remote code execution allows for comprehensive compromise of the affected application's data integrity, confidentiality, and availability. Attackers may use this foothold to exfiltrate sensitive customer information, deface websites, install additional malware such as botnets or ransomware, or pivot further into internal network segments if the server is part of a larger infrastructure.
This specific vulnerability aligns with several tactics in the MITRE ATT&CK framework, particularly those related to Initial Access and Execution. The act of uploading malicious files corresponds to techniques involving web shell deployment, which serves as a persistent backdoor for continued unauthorized access. Furthermore, because the exploit has been released publicly, the barrier to entry for potential attackers is significantly lowered. This widespread availability increases the likelihood of automated scanning tools targeting vulnerable instances across the internet, leading to rapid exploitation at scale. The fact that the project maintainers have not yet responded to early issue reports exacerbates the risk profile, leaving users without official patches or guidance on how to mitigate the exposure in their current deployments.
To address this critical security flaw, immediate remediation steps are required for administrators of affected iWebShop installations. The most effective mitigation is upgrading to a patched version of the software once one becomes available from the project maintainers. In the interim, organizations should implement strict file upload restrictions at the web server or application firewall level. This includes enforcing allowlists that only permit specific image formats such as JPEG, PNG, and GIF while rejecting executable extensions like PHP, ASP, JSP, and HTML. Additionally, deploying files to a directory with no execute permissions can prevent successful code execution even if malicious files are uploaded. Implementing content validation mechanisms that inspect the actual file signature rather than relying solely on file extensions is also crucial for defense in depth. Regular security audits and penetration testing should be conducted to identify similar weaknesses in other parts of the application logic, ensuring a robust posture against evolving cyber threats.