CVE-2019-7228 in IDAL
Summary
by MITRE
The ABB IDAL HTTP server mishandles format strings in a username or cookie during the authentication process. Attempting to authenticate with the username %25s%25p%25x%25n will crash the server. Sending %08x.AAAA.%08x.%08x will log memory content from the stack.
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Analysis
by VulDB Data Team • 10/09/2023
The CVE-2019-7228 vulnerability affects the ABB IDAL HTTP server, a critical component in industrial automation systems that handles authentication requests through HTTP protocols. This flaw represents a classic format string vulnerability that exploits improper input validation during the authentication process, specifically targeting how the server processes username and cookie parameters. The vulnerability demonstrates a fundamental security weakness in the server's string handling mechanisms, where user-supplied data is directly used in printf-style functions without proper sanitization or validation.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious authentication requests containing specially formatted strings such as %25s%25p%25x%25n or %08x.AA AA.%08x.%08x. These sequences leverage the format string vulnerability by using percent-encoded characters that translate to format specifiers in the server's processing logic. When the server attempts to authenticate users with these malformed inputs, the improper handling of format strings causes the HTTP server to crash completely, resulting in a denial of service condition that disrupts industrial automation services. The vulnerability operates at the application layer and can be exploited remotely without requiring authentication, making it particularly dangerous in industrial control environments.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromising industrial control system integrity. In industrial environments where ABB IDAL servers manage critical infrastructure, a crash can lead to production halts, safety system failures, or unauthorized access to operational controls. The memory disclosure aspect of the vulnerability, where %08x sequences reveal stack memory content, provides attackers with sensitive information that could aid in further exploitation attempts. This memory leakage can expose system internals, cryptographic keys, or other sensitive data that might be stored in memory during authentication processes, creating additional attack vectors beyond simple denial of service.
This vulnerability maps directly to CWE-134, which describes the weakness of using user-supplied format strings in functions that perform formatting operations. The flaw also aligns with ATT&CK technique T1210, which covers exploitation of remote services through the use of system binaries or applications that do not properly validate input. Organizations should implement immediate mitigations including input validation and sanitization of all authentication parameters, particularly those that might contain format specifiers. Network segmentation and access controls should be enforced to limit exposure of industrial servers to untrusted networks, while regular security assessments should verify that all industrial control system components have been patched against known vulnerabilities. The incident highlights the critical need for secure coding practices in industrial environments where software reliability directly impacts operational safety and business continuity.