CVE-2019-1966 in UCS Fabric Interconnect Software
Summary
by MITRE
A vulnerability in a specific CLI command within the local management (local-mgmt) context for Cisco UCS Fabric Interconnect Software could allow an authenticated, local attacker to gain elevated privileges as the root user on an affected device. The vulnerability is due to extraneous subcommand options present for a specific CLI command within the local-mgmt context. An attacker could exploit this vulnerability by authenticating to an affected device, entering the local-mgmt context, and issuing a specific CLI command and submitting user input. A successful exploit could allow the attacker to execute arbitrary operating system commands as root on an affected device. The attacker would need to have valid user credentials for the device.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 12/11/2023
This vulnerability resides within Cisco UCS Fabric Interconnect Software where a specific command in the local management context contains extraneous subcommand options that create an unexpected privilege escalation path. The flaw exists in the command line interface implementation where improper input validation allows malicious command sequences to be executed with elevated privileges. The vulnerability specifically affects the local-mgmt context which is designed for administrative operations but contains a command that does not properly sanitize user inputs before processing them as system commands. This represents a classic privilege escalation vulnerability that leverages command injection techniques within a trusted administrative context.
The technical exploitation requires an authenticated attacker who must first establish valid credentials to access the device and then navigate to the local-mgmt context where the vulnerable command is available. Once inside this context, the attacker can issue a specific CLI command that accepts user input without proper sanitization or validation, allowing the attacker to inject malicious command sequences that execute with root privileges. This vulnerability directly relates to CWE-78 which describes improper neutralization of special elements used in OS commands, and CWE-20 which covers input validation issues. The attack vector operates through command line interface manipulation and demonstrates how seemingly benign administrative interfaces can become attack surfaces when proper input handling is not implemented.
The operational impact of this vulnerability is severe as it provides attackers with complete system compromise capabilities. Successful exploitation allows execution of arbitrary operating system commands as the root user, which means attackers can modify system files, install malicious software, access sensitive data, and potentially escalate their access to other connected systems. This vulnerability essentially provides a backdoor to full system control, making it particularly dangerous for network infrastructure devices that serve as critical points of connectivity and control. The attack requires only valid user credentials, making it more accessible than attacks requiring physical access or more sophisticated initial compromise techniques.
Mitigation strategies should focus on implementing proper input validation and sanitization for all CLI commands within the local-mgmt context. Cisco has released patches addressing this vulnerability through software updates that correct the command processing logic to properly validate and sanitize user inputs. Organizations should immediately apply the relevant security patches to all affected devices and implement network segmentation to limit access to administrative interfaces. Additionally, enforcing principle of least privilege access controls and monitoring CLI command usage can help detect potential exploitation attempts. The vulnerability aligns with ATT&CK technique T1068 which covers exploit for privilege escalation and T1059 which covers command and scripting interpreter. Regular security assessments of administrative interfaces and proper configuration management practices should be implemented to prevent similar vulnerabilities from emerging in other system components.