CVE-2019-7232 in IDAL
Summary
by MITRE
The ABB IDAL HTTP server is vulnerable to a buffer overflow when a long Host header is sent in a web request. The Host header value overflows a buffer and overwrites a Structured Exception Handler (SEH) address. An unauthenticated attacker can submit a Host header value of 2047 bytes or more to overflow the buffer and overwrite the SEH address, which can then be leveraged to execute attacker-controlled code on the server.
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Analysis
by VulDB Data Team • 10/07/2023
The CVE-2019-7232 vulnerability affects the ABB IDAL HTTP server, a component commonly used in industrial automation and control systems. This vulnerability represents a classic buffer overflow condition that occurs when processing HTTP requests containing excessively long Host headers. The flaw exists within the server's request handling mechanism where input validation is insufficient to prevent maliciously crafted header values from exceeding allocated buffer boundaries. The vulnerability is particularly concerning in industrial environments where ABB IDAL servers may be exposed to untrusted networks or where security boundaries are not properly enforced.
The technical exploitation of this vulnerability relies on the specific memory layout of the affected HTTP server implementation. When a Host header exceeding 2047 bytes is submitted, the buffer overflow extends beyond the allocated memory space and directly overwrites the Structured Exception Handler (SEH) chain within the Windows process memory structure. This overwrite occurs because the server's implementation does not properly validate the length of the Host header value before copying it into a fixed-size buffer. The SEH mechanism is a Windows security feature designed to handle exceptions and errors, making it a prime target for exploitation as it allows attackers to redirect program execution flow.
The operational impact of this vulnerability is severe and potentially catastrophic for industrial control systems. An unauthenticated attacker can leverage this vulnerability to execute arbitrary code on the server with the privileges of the running process, typically SYSTEM level access on Windows systems. This remote code execution capability enables attackers to gain full control over the affected server, potentially leading to complete system compromise and disruption of industrial processes. The vulnerability is particularly dangerous because it does not require any authentication, making it accessible to anyone who can send HTTP requests to the server. The attack can be executed through simple HTTP requests, making it easily exploitable in environments where the server is accessible from external networks.
From a cybersecurity perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and demonstrates the importance of proper input validation and bounds checking in security-critical applications. The ATT&CK framework categorizes this as a privilege escalation technique through code injection, potentially enabling further lateral movement within industrial networks. Organizations should implement immediate mitigations including network segmentation to isolate affected servers, disabling unnecessary HTTP services, and applying vendor-provided patches as soon as they become available. Additionally, monitoring for unusually long Host headers in network traffic can serve as an early detection mechanism for potential exploitation attempts. The vulnerability underscores the critical need for robust input validation and memory safety practices in industrial control system software, particularly in environments where security considerations may be secondary to operational requirements.