CVE-2016-4922 in Junos
Summary
by MITRE
Certain combinations of Junos OS CLI commands and arguments have been found to be exploitable in a way that can allow unauthorized access to the operating system. This may allow any user with permissions to run these CLI commands the ability to achieve elevated privileges and gain complete control of the device. Affected releases are Juniper Networks Junos OS 11.4 prior to 11.4R13-S3; 12.1X46 prior to 12.1X46-D60; 12.1X47 prior to 12.1X47-D45; 12.3 prior to 12.3R12; 12.3X48 prior to 12.3X48-D35; 13.2 prior to 13.2R9; 13.3 prior to 13.3R4-S11, 13.3R9; 14.1 prior to 14.1R4-S12, 14.1R7; 14.1X53 prior to 14.1X53-D28, 14.1X53-D40; 14.1X55 prior to 14.1X55-D35; 14.2 prior to 14.2R3-S10, 14.2R4-S7, 14.2R5; 15.1 prior to 15.1F4, 15.1R3; 15.1X49 prior to 15.1X49-D60; 15.1X53 prior to 15.1X53-D57, 15.1X53-D70.
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Analysis
by VulDB Data Team • 09/26/2022
This vulnerability represents a critical privilege escalation flaw in Juniper Networks Junos OS that allows authenticated users to gain elevated system privileges through specific combinations of command line interface commands and arguments. The vulnerability falls under the category of command injection and privilege escalation as defined by CWE-264, where legitimate administrative commands are manipulated to bypass normal access controls and achieve unauthorized elevated privileges. The flaw specifically affects multiple major release branches of Junos OS, spanning versions from 11.4 through 15.1, indicating a widespread issue that has persisted across several years of development cycles.
The technical nature of this vulnerability stems from insufficient input validation and privilege checking mechanisms within the CLI processing subsystem. When certain command sequences are executed with specific arguments, the system fails to properly validate user permissions or sanitize command inputs, creating a pathway for privilege escalation. This type of vulnerability is particularly dangerous because it operates within the legitimate administrative interface, making it difficult to detect through standard security monitoring. The issue is classified as a privilege escalation vulnerability under ATT&CK framework category T1068, where adversaries leverage legitimate system tools to elevate their privileges.
The operational impact of this vulnerability is severe as it allows any user who can execute the affected CLI commands to potentially gain complete administrative control of the network device. This means that even users with limited privileges could exploit the flaw to access sensitive system functions, modify configurations, read confidential data, or even install malicious software on the device. Network administrators who rely on standard CLI access controls for security would be vulnerable to this attack vector, as the exploitation does not require external network access or sophisticated attack techniques. The vulnerability essentially undermines the principle of least privilege that is fundamental to network security architectures.
Mitigation strategies for this vulnerability require immediate patching of affected Junos OS versions with the appropriate security updates provided by Juniper Networks. Organizations should prioritize upgrading all affected devices to the patched versions specified in the vendor advisories, particularly focusing on the specific release branches mentioned in the CVE description. Network segmentation and access control measures should be implemented to limit who can access the CLI interface, although this provides only partial protection since the vulnerability affects legitimate administrative functionality. Additionally, organizations should conduct comprehensive audits of their Junos OS installations to identify all potentially affected devices and implement monitoring for suspicious CLI activity that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be performed to ensure that no other similar flaws exist within the network infrastructure.