CVE-2015-4455 Scanner

The WordPress Plugin Aviary Image Editor Add-on For Gravity Forms is widely used by website administrators to enhance the functionality of Gravity Forms in WordPress. This plugin provides advanced image editing features integrated directly within the Gravity Forms environment. Web developers and content creators leverage this tool to allow users to modify images effortlessly as part of form submission processes. Its widespread adoption is due to its ease of use and powerful editing capabilities, making it a popular choice for both individual bloggers and professional site maintainers. By offering seamless image editing in forms, it serves as a valuable tool for enhancing user engagement and content quality. However, like many plugins, it also requires vigilant updates and oversight to ensure security within the WordPress ecosystem.

The Unrestricted File Upload vulnerability allows attackers to upload files with executable extensions, potentially leading to arbitrary code execution. This vulnerability arises when user inputs through file uploads are insufficiently validated, permitting files with potentially malicious content to be processed by the server. When an attacker successfully uploads a malicious file, they can execute it remotely, leading to the potential takeover of the server. The vulnerability becomes critical as it does not require authentication, thus permitting any remote user to exploit it. As such, it remains a significant risk for sites running vulnerable versions of the plugin.

The vulnerability in this plugin specifically involves the endpoint responsible for handling file uploads found in the 'includes/upload.php' file. Attackers leverage a bypass via the form parameters to upload a file with an executable extension under the 'wp-content/uploads/gform_aviary' directory. This exploits insufficient server-side validation checks, particularly in distinguishing executable files from non-threatening ones. As demonstrated in the exposed form, directory traversal can be used to specify undesirable upload paths. The server then treats these files favorably, enabling access via direct requests, potentially resulting in arbitrary code execution on the server. This technical oversight presents a severe risk requiring immediate attention.

Exploiting this vulnerability can have severe consequences, including unauthorized access to sensitive data, defacement of web pages, or complete server takeover. An attacker with the ability to execute arbitrary code can modify or delete content, steal confidential information, or plant malware on a site. Such breaches can result in downtime, data loss, and reputational damage for affected sites. Additionally, compromised servers can be used as a launching pad for further attacks on connected systems or as part of a botnet. As such, the potential effects highlight the crucial importance of addressing this vulnerability promptly and effectively.

REFERENCES

• https://nvd.nist.gov/vuln/detail/CVE-2015-4455
• http://packetstormsecurity.com/files/132256/WordPress-Aviary-Image-Editor-Add-On-For-Gravity-Forms-3.0-Beta-Shell-Upload.html