CVE-2021-26729 in IAC-AST2500A
Summary
by MITRE • 10/24/2022
Command injection and multiple stack-based buffer overflows vulnerabilities in the Login_handler_func function of spx_restservice allow an attacker to execute arbitrary code with the same privileges as the server user (root). This issue affects: Lanner Inc IAC-AST2500A standard firmware version 1.10.0.
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Analysis
by VulDB Data Team • 11/19/2022
The vulnerability identified as CVE-2021-26729 represents a critical security flaw in the Lanner Inc IAC-AST2500A industrial automation device firmware version 1.10.0. This issue manifests through two distinct but interconnected attack vectors within the Login_handler_func function of the spx_restservice component. The vulnerability stems from inadequate input validation and improper memory management practices that create exploitable conditions for both command injection and stack-based buffer overflow attacks. The affected device operates within industrial control systems where unauthorized code execution could have severe operational consequences.
The technical implementation of this vulnerability involves the Login_handler_func function failing to properly sanitize user-supplied input before processing it within the web service framework. When an attacker submits malicious data through the login interface, the system does not adequately validate or escape special characters that could be interpreted as command sequences or buffer manipulation instructions. This lack of input sanitization creates a direct pathway for command injection attacks where arbitrary shell commands can be executed within the context of the spx_restservice process. The stack-based buffer overflows occur due to insufficient bounds checking when handling user input, allowing attackers to overwrite adjacent memory locations and potentially manipulate program execution flow.
The operational impact of this vulnerability is particularly severe given that the affected device operates with root privileges, meaning successful exploitation would grant attackers complete control over the system. Industrial automation devices like the IAC-AST2500A typically serve as critical infrastructure components in manufacturing and control environments, where unauthorized access could lead to production disruption, data compromise, or even physical safety hazards. The vulnerability affects a specific firmware version, indicating that this issue was likely introduced through improper code development practices or insufficient security testing during the firmware development lifecycle. Attackers could leverage this vulnerability to establish persistent access, escalate privileges further, or use the compromised device as a pivot point for attacking other systems within the industrial network.
Security mitigations for this vulnerability should prioritize immediate firmware updates from Lanner Inc to address the identified code flaws in the Login_handler_func function. Organizations should implement network segmentation to limit access to the affected device and deploy intrusion detection systems to monitor for suspicious login attempts or command execution patterns. The vulnerability aligns with CWE-78 for command injection and CWE-121 for stack-based buffer overflow, both of which are categorized under the Common Weakness Enumeration framework for software security weaknesses. From an attack perspective, this vulnerability maps to ATT&CK techniques including T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation, making it a significant concern for industrial cybersecurity frameworks. Additionally, organizations should conduct thorough security assessments of their industrial control systems to identify similar vulnerabilities in other firmware components and establish robust patch management procedures for critical infrastructure devices.