CVE-2026-27350 in Builderius Plugin
Summary
by MITRE • 10/10/2026
Server-Side Request Forgery (SSRF) vulnerability in Builderius.io Builderius allows Server Side Request Forgery.
This issue affects Builderius: from 1.4 through 1.4-beta.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/10/2026
The identified security flaw represents a classic Server-Side Request Forgery, or SSRF, vulnerability within the Builderius web application platform, specifically impacting versions ranging from 1.4 up to and including version 1.4-beta. This type of vulnerability arises when an application accepts user-supplied input that is subsequently used by the server to construct URLs for making HTTP requests without adequate validation or sanitization mechanisms in place. In this specific instance, the Builderius software fails to properly restrict the destinations to which it can send outbound network connections based on user-provided data. This lack of rigorous input control allows an attacker to manipulate the application into fetching resources from arbitrary internal and external locations that would otherwise be inaccessible directly by the client or restricted by firewall rules designed to protect sensitive backend infrastructure.
From a technical perspective, the core issue lies in the insufficient validation of URL parameters passed through the Builderius interface. When the server processes these inputs, it constructs requests targeting specific endpoints without verifying whether those targets reside within an allowed whitelist of domains or IP ranges. Consequently, an attacker can craft malicious payloads that direct the vulnerable application to access internal services such as database management interfaces, cloud metadata endpoints like AWS EC2 instance metadata service at 169.254.169.254, or other private network resources. This capability effectively bypasses perimeter security controls because the requests originate from a trusted server IP address rather than an external attacker's machine, thereby tricking internal firewalls and access control lists into permitting traffic that should be blocked if initiated externally.
The operational impact of this vulnerability is significant and multifaceted, primarily centering on unauthorized information disclosure and potential remote code execution through chained attacks. By leveraging SSRF to probe internal network services, an attacker can extract sensitive configuration files, database credentials stored in environment variables, or cloud provider metadata that contains temporary security tokens and access keys. These stolen credentials can then be used to escalate privileges within the affected infrastructure. Furthermore, if specific internal services are vulnerable to other exploits, such as deserialization flaws or command injection, the SSRF vulnerability serves as a critical entry point to trigger those secondary vulnerabilities from inside the network perimeter. This transforms a relatively simple input validation error into a severe compromise of system integrity and confidentiality.
In terms of industry classification standards, this flaw aligns with CWE-918, which defines Server-Side Request Forgery (SSRF) flaws where web applications allow users to specify URLs that are fetched by the server side code. Additionally, from an offensive security perspective as mapped in the MITRE ATT&CK framework, this vulnerability facilitates techniques associated with Discovery and Collection phases, specifically allowing adversaries to gather information about internal network architecture and service configurations through T1046 Service Scan or T1537 Transfer Data to Cloud Account if cloud metadata is accessed. The ability to pivot from an external web application into the internal network underscores the critical nature of this misconfiguration in modern web deployment architectures that rely on microservices and containerized environments behind reverse proxies.
To mitigate this vulnerability, immediate remediation actions must focus on implementing strict input validation and output encoding strategies within the Builderius codebase or its configuration settings if available. The most effective defense involves maintaining a whitelist of allowed domains and IP addresses for any outbound requests initiated by the application. Developers should reject all URLs that do not match predefined safe patterns, explicitly blocking private IP ranges such as 10.x.x.x, 172.16-31.x.x, 192.168.x.x, and loopback address 127.0.0.1 to prevent access to internal services. Additionally, implementing a network-level proxy that filters outbound traffic from the application server can provide an additional layer of defense by inspecting and blocking requests destined for unauthorized destinations regardless of how they are constructed within the application logic. Upgrading to patched versions released after 1.4-beta is also essential as these updates likely contain code changes addressing this specific input validation gap.