CVE-2018-15776 in iDRAC7
Summary
by MITRE
Dell EMC iDRAC7/iDRAC8 versions prior to 2.61.60.60 contain an improper error handling vulnerability. An unauthenticated attacker with physical access to the system could potentially exploit this vulnerability to get access to the u-boot shell.
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Analysis
by VulDB Data Team • 04/20/2020
The vulnerability identified as CVE-2018-15776 affects Dell EMC iDRAC7 and iDRAC8 management controllers running firmware versions prior to 2.61.60.60. This represents a critical security flaw that stems from improper error handling within the firmware implementation. The issue specifically impacts the u-boot bootloader environment which serves as the foundational firmware layer for system initialization and boot processes. The vulnerability exists in how the management controller handles certain error conditions during the boot sequence, creating potential attack vectors that could be exploited by adversaries with physical access to the target system.
The technical flaw manifests through insufficient error handling mechanisms that fail to properly validate or sanitize input during boot processes. When the iDRAC controller encounters certain error conditions, the system does not properly terminate or redirect execution flow, instead allowing potential access to the u-boot shell environment. This improper error handling creates a pathway where an attacker could bypass normal authentication mechanisms and gain direct access to low-level system interfaces. The u-boot shell provides extensive control over system boot parameters, memory operations, and hardware initialization sequences, making it a highly valuable target for attackers seeking persistent system compromise. This vulnerability aligns with CWE-248, which addresses "Uncaught Exception" conditions where programs fail to handle exceptions properly, and represents a classic case of inadequate error recovery mechanisms in embedded firmware systems.
The operational impact of this vulnerability is significant for organizations relying on Dell EMC servers with affected iDRAC versions. An attacker with physical access to the system can exploit this weakness to gain root-level access to the u-boot shell without requiring authentication credentials. This capability enables the attacker to modify boot parameters, load malicious firmware, or access sensitive system information that would normally be protected by proper authentication mechanisms. The vulnerability essentially undermines the fundamental security model of the management controller by allowing unauthorized access to system-level interfaces that should remain protected. Organizations may face potential data breaches, system compromise, or complete loss of control over affected servers, particularly in environments where physical security controls are inadequate or compromised.
Mitigation strategies for CVE-2018-15776 primarily involve updating the iDRAC firmware to version 2.61.60.60 or later, which addresses the improper error handling vulnerability. Dell has released patched firmware versions that correct the error handling mechanisms within the u-boot environment and prevent unauthorized access to the shell interface. System administrators should also implement additional physical security measures including restricted access to server locations, proper key management for physical access controls, and monitoring for unauthorized physical access attempts. The vulnerability demonstrates the importance of proper firmware error handling and aligns with ATT&CK technique T1005 which covers "Data from Local System" and T1068 which covers "Exploitation for Privilege Escalation." Organizations should also consider implementing network-based monitoring to detect potential exploitation attempts and maintain comprehensive audit trails of management controller access and configuration changes. Regular firmware updates and vulnerability assessments should be part of standard security operations to prevent similar issues in the future.