CVE-2019-0070 in Junos
Summary
by MITRE
An Improper Input Validation weakness allows a malicious local attacker to elevate their permissions to take control of other portions of the NFX platform they should not be able to access, and execute commands outside their authorized scope of control. This leads to the attacker being able to take control of the entire system. This issue affects: Juniper Networks Junos OS versions prior to 18.2R1 on NFX Series.
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Analysis
by VulDB Data Team • 01/07/2024
The vulnerability identified as CVE-2019-0070 represents a critical improper input validation weakness within Juniper Networks Junos OS versions prior to 18.2R1 on NFX Series devices. This flaw exists at the core of the platform's permission validation mechanisms, creating a pathway for malicious local attackers to bypass authorization controls and escalate their privileges. The vulnerability specifically targets the input validation processes that govern user access rights and system command execution, allowing unauthorized users to exploit the system's trust model and gain elevated access privileges.
The technical implementation of this weakness enables an attacker with local access to manipulate input parameters that should be strictly validated and restricted. When the system processes user inputs without proper sanitization or validation checks, it creates opportunities for privilege escalation attacks that can result in complete system compromise. The flaw operates by allowing malicious input to traverse the normal authorization boundaries, effectively breaking down the security controls that separate different user roles and system components. This improper validation creates a direct attack vector that can be exploited through carefully crafted input sequences that manipulate the system's permission handling logic.
The operational impact of CVE-2019-0070 extends far beyond simple unauthorized access, as it provides attackers with the capability to execute arbitrary commands outside their authorized scope of control. This privilege escalation vulnerability allows attackers to gain control over other portions of the NFX platform that they should not normally be able to access, effectively breaking down the system's security isolation mechanisms. The consequences include complete system compromise where attackers can manipulate system configurations, access sensitive data, install malicious software, and potentially use the compromised device as a launch point for further attacks against the broader network infrastructure. This vulnerability undermines the fundamental security model of the platform and creates persistent access for malicious actors.
Mitigation strategies for CVE-2019-0070 must prioritize immediate system updates to Junos OS version 18.2R1 or later, which contain the necessary patches to address the improper input validation weakness. Organizations should also implement strict access controls and monitoring of local system access, as well as conduct thorough security audits of all NFX Series devices running vulnerable software versions. Network segmentation and privilege separation measures can help limit the potential impact of successful exploitation attempts, while continuous monitoring of system logs and access patterns can aid in early detection of unauthorized activities. This vulnerability aligns with CWE-20, which describes improper input validation as a common weakness that leads to various security issues including privilege escalation and arbitrary code execution. The attack pattern follows typical privilege escalation techniques documented in the MITRE ATT&CK framework, specifically targeting the privilege escalation and defense evasion tactics that allow attackers to maintain persistent access and expand their control over affected systems.