CVE-2019-0061 in Junos
Summary
by MITRE
The management daemon (MGD) is responsible for all configuration and management operations in Junos OS. The Junos CLI communicates with MGD over an internal unix-domain socket and is granted special permission to open this protected mode socket. Due to a misconfiguration of the internal socket, a local, authenticated user may be able to exploit this vulnerability to gain administrative privileges. This issue only affects Linux-based platforms. FreeBSD-based platforms are unaffected by this vulnerability. Exploitation of this vulnerability requires Junos shell access. This issue cannot be exploited from the Junos CLI. This issue affects Juniper Networks Junos OS: 15.1X49 versions prior to 15.1X49-D171, 15.1X49-D180; 15.1X53 versions prior to 15.1X53-D496, 15.1X53-D69; 16.1 versions prior to 16.1R7-S4; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R1-S8, 17.2R2-S7, 17.2R3-S1; 17.3 versions prior to 17.3R3-S4; 17.4 versions prior to 17.4R1-S6, 17.4R1-S7, 17.4R2-S3, 17.4R3; 18.1 versions prior to 18.1R2-S4, 18.1R3-S4; 18.2 versions prior to 18.2R1-S5, 18.2R2-S2, 18.2R3; 18.3 versions prior to 18.3R1-S3, 18.3R2; 18.4 versions prior to 18.4R1-S2, 18.4R2.
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Analysis
by VulDB Data Team • 01/05/2024
The vulnerability identified as CVE-2019-0061 resides within the management daemon (MGD) of Junos OS, which serves as the central component for all configuration and management operations. This daemon communicates with the Junos command-line interface through an internal unix-domain socket that is designed with special permissions to ensure only authorized processes can access it. The flaw manifests in a misconfiguration of this protected socket mechanism, creating a path for privilege escalation. The vulnerability specifically impacts Linux-based platforms running Junos OS, while FreeBSD-based systems remain unaffected, indicating a platform-specific implementation issue. The security model relies on the assumption that only legitimate Junos shell processes can establish connections to this privileged socket, but the misconfiguration allows for unauthorized access patterns.
The technical exploitation of this vulnerability requires a local, authenticated user to already possess Junos shell access, meaning the attacker must first have some form of legitimate login credentials to the system. This prerequisite places the vulnerability in the category of local privilege escalation rather than remote code execution. The misconfiguration essentially allows an authenticated user to bypass the normal permission controls that should restrict access to the MGD socket, enabling them to perform administrative operations that should be restricted to privileged users. This represents a failure in the principle of least privilege and undermines the security boundaries that separate normal user operations from administrative functions. The vulnerability is classified under CWE-276 as inadequate privilege management, and the attack vector aligns with ATT&CK technique T1068 which covers privilege escalation through local exploits.
The operational impact of this vulnerability is significant for organizations running affected Junos OS versions on Linux platforms, as it allows a compromised local account to potentially gain full administrative control over network devices. This could enable attackers to modify configurations, disable security features, or establish persistent access points within the network infrastructure. The vulnerability affects a broad range of Junos OS versions across multiple release branches, making it widespread among affected deployments. Organizations with multiple network devices running these vulnerable versions face a substantial risk, as a single compromised account could provide access to an entire network infrastructure. The affected versions span from 15.1X49 through 18.4R2, indicating that this vulnerability has been present for several major releases and affects both legacy and more recent versions of the operating system.
Mitigation strategies for CVE-2019-0061 primarily focus on applying the appropriate software patches released by Juniper Networks to address the socket misconfiguration issue. Organizations should immediately upgrade to the patched versions specified in the vulnerability advisories for their respective Junos OS version lines. System administrators should also implement additional security measures including strict access controls, monitoring of privileged socket connections, and regular security audits of network device configurations. The implementation of network segmentation and least privilege principles can help limit the potential impact even if the vulnerability is exploited. Additionally, organizations should conduct thorough vulnerability assessments to identify all affected devices and ensure that the patches are properly applied across all network infrastructure components. The remediation process should include verification that the socket permissions have been correctly restored and that the management daemon properly enforces access controls. Security monitoring should be enhanced to detect unusual patterns of socket access that might indicate exploitation attempts, as this vulnerability represents a critical weakness in the local privilege escalation controls of Junos OS implementations.