CVE-2025-36178 in Controller
Summary
by MITRE • 09/18/2026
IBM Controller 11.0.0 through 11.0.1 FP7, and 11.1.0 through 11.1.3 FP1 could allow an authenticated user to bypass input validation due to improper validation of client-side input of file size.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in IBM Controller versions ranging from 11.0.0 through 11.0.1 Fix Pack 7, and 11.1.0 through 11.1.3 Fix Pack 1, represents a significant security flaw rooted in the improper validation of client-side input regarding file size limits. This issue classifies as an Insufficient Input Validation vulnerability, which aligns with Common Weakness Enumeration identifier CWE-20. The core technical failure lies in the application's reliance on client-side mechanisms to enforce constraints on uploaded files rather than implementing robust server-side verification. In secure software architecture, input validation must be performed exclusively or primarily on the server side because client-side controls can be easily bypassed by an attacker manipulating network requests using standard proxy tools or custom scripts. By trusting the file size parameter sent from the user's browser without independent confirmation at the application layer, IBM Controller exposes itself to exploitation where malicious actors can submit files that exceed intended limits.
From a technical perspective, this flaw allows an authenticated user to upload files of arbitrary sizes, potentially leading to resource exhaustion or denial of service conditions against the server infrastructure. When large files are processed by systems not designed for such volume without proper throttling or quota enforcement, it can consume excessive disk space, memory, and CPU cycles. This operational impact may degrade system performance for legitimate users or cause complete unavailability of the IBM Controller application if storage resources are fully depleted. Furthermore, depending on how the uploaded files are handled downstream within the enterprise environment, excessively large files could trigger buffer overflows in other components that process these inputs, potentially leading to remote code execution scenarios although the primary vector described is input validation bypass. The vulnerability underscores a critical misconfiguration where security controls intended for data integrity and resource management were inadequately implemented at the backend processing stage.
The exploitation of this weakness requires authentication, meaning an attacker must possess valid credentials within the IBM Controller environment before attempting to leverage this flaw. This requirement limits the attack surface to insider threats or compromised accounts rather than unauthenticated external attackers. However, even with authenticated access, the ability to bypass file size restrictions can facilitate data exfiltration by uploading large volumes of sensitive information out of the organization if upload functionality is permitted for outbound transfers. It also complicates forensic analysis and log management as oversized logs or audit trails generated from processing these files could overwhelm logging subsystems. The lack of server-side validation means that standard security monitoring tools may not immediately flag anomalous behavior associated with unusually large file uploads, allowing the attack to proceed undetected until resource constraints become critical.
To mitigate this vulnerability, organizations must ensure they apply the relevant fix packs provided by IBM for their specific version of Controller. For systems running 11.0.x versions, applying Fix Pack 7 or later is essential, while users on the 11.1.x branch should update to Fix Pack 1 or newer releases that address this input validation logic. In addition to patching, administrators should implement network-level controls such as web application firewalls configured with strict payload size limits for file upload endpoints. These perimeter defenses act as a secondary layer of security, ensuring that even if the application itself fails to validate inputs correctly, malicious requests are dropped before reaching the vulnerable code path. Regular audits of input validation practices across all enterprise applications should be conducted to prevent similar CWE-20 weaknesses from being introduced in future development cycles or third-party integrations.