CVE-2021-26732 in IAC-AST2500A
Summary
by MITRE • 10/24/2022
A broken access control vulnerability in the First_network_func function of spx_restservice allows an attacker to arbitrarily change the network configuration of the BMC. 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
This vulnerability represents a critical broken access control flaw that undermines the security posture of embedded network management systems. The issue resides within the First_network_func function of the spx_restservice component, which governs network configuration operations for BMC (Baseboard Management Controller) systems. The vulnerability allows unauthorized actors to manipulate network settings without proper authentication or authorization, effectively compromising the network infrastructure that the BMC manages. This particular exposure affects Lanner Inc's IAC-AST2500A hardware platform running firmware version 1.10.0, where the REST API service fails to properly validate incoming requests for network configuration changes. The flaw stems from inadequate input validation and insufficient access control mechanisms within the network management function, creating a pathway for privilege escalation and unauthorized system modification. According to CWE-284, this vulnerability maps directly to improper access control conditions where the system grants privileges to unauthorized users. The security implications extend beyond simple network configuration changes, as BMC systems typically serve as critical management interfaces for server hardware, making this vulnerability particularly dangerous in enterprise environments where physical security and network isolation are paramount.
The technical exploitation of this vulnerability occurs through the REST API interface of the spx_restservice component, where attackers can craft malicious requests to modify network parameters such as IP addresses, subnet masks, gateway configurations, and DNS settings. This allows for potential man-in-the-middle attacks, network segmentation bypasses, or complete network isolation of target systems. The vulnerability's impact is amplified because BMCs often operate in privileged network segments and maintain persistent connections to management systems, making unauthorized network changes particularly damaging. Attackers could potentially redirect network traffic through compromised BMCs, enabling further reconnaissance or lateral movement within the network infrastructure. This represents a direct violation of the principle of least privilege, where the system fails to enforce proper authorization checks before allowing network configuration modifications. The ATT&CK framework categorizes this as a privilege escalation technique under T1068, where adversaries leverage system vulnerabilities to gain elevated permissions. The vulnerability's exploitation requires minimal technical expertise since it involves standard REST API manipulation techniques, making it accessible to threat actors across different skill levels.
The operational impact of this vulnerability extends far beyond immediate network configuration changes, as BMC systems serve as crucial points of hardware management and monitoring for enterprise infrastructure. When compromised, attackers can effectively gain administrative control over network connectivity for managed servers, potentially leading to complete system isolation or redirection of management traffic. This vulnerability undermines the fundamental security assumptions of hardware management interfaces, where BMCs are expected to provide secure, authenticated access to system configuration parameters. Organizations running affected Lanner IAC-AST2500A systems face significant risk of unauthorized network access, potential data exfiltration through modified routing configurations, and disruption of critical network services. The vulnerability's persistence is particularly concerning since BMC firmware updates often occur infrequently, meaning affected systems may remain vulnerable for extended periods without proper patching. Network administrators must consider the potential for this vulnerability to be used in conjunction with other attack vectors, as compromised BMCs can serve as persistent backdoors for attackers seeking long-term access to target networks. The attack surface expands significantly when considering that BMC systems typically maintain network connectivity even during system shutdowns, providing attackers with continuous access windows. This vulnerability directly impacts the availability and integrity of network infrastructure, potentially causing service disruptions or enabling sophisticated attack campaigns targeting the broader enterprise network ecosystem.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security posture improvements. Organizations should immediately apply firmware updates from Lanner Inc to address the specific access control flaw in the spx_restservice component. Network segmentation should be implemented to isolate BMC management interfaces from general network traffic, reducing the attack surface for unauthorized access attempts. The principle of least privilege must be enforced through proper authentication mechanisms and role-based access controls for all BMC management interfaces. Regular security assessments of BMC systems should include vulnerability scanning for access control weaknesses and configuration reviews to ensure proper network isolation. Network monitoring solutions should be deployed to detect anomalous network configuration changes that might indicate exploitation attempts. Additional protective measures include implementing secure remote access protocols, disabling unnecessary network services on BMC interfaces, and establishing automated alerting for unauthorized configuration modifications. Security teams should also consider implementing network access control lists and firewall rules specifically targeting BMC management ports to prevent unauthorized access from external networks. The vulnerability highlights the importance of secure coding practices and proper input validation in embedded systems, particularly those handling critical infrastructure management functions. Organizations should also establish incident response procedures specifically addressing BMC compromise scenarios, as these systems often require specialized recovery procedures due to their role in hardware management and system recovery operations.