CVE-2026-102079 in Junos OS
Summary
by MITRE • 10/14/2026
An OS command injection vulnerability in the CLI of Juniper Networks Junos OS allows a local, low privileged attacker to take complete control of the device.
A specific 'request csds' command doesn't sanitize user provided input so that it can be interpreted as a command. This allows unintended command execution with root privileges, which can lead to unauthorized system access or modification.
This issue affects Junos OS:
* 24.4 versions before 24.4R2-S4; * 25.2 versions before 25.2R2-S1; * 25.4 versions before 25.4R1-S3;
This issue does not affect Junos OS releases before 24.4R1.
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Analysis
by VulDB Data Team • 10/15/2026
The identified vulnerability represents a critical security flaw within the command-line interface of Juniper Networks Junos Operating System, specifically affecting local operations performed by low-privileged users. This weakness is classified as an operating system command injection, where insufficient sanitization of user-supplied input allows for the execution of arbitrary commands with elevated privileges. The root cause lies in a specific administrative function, identified as the 'request csds' command, which fails to properly validate or escape special characters and shell metacharacters provided by the attacker. Because this processing occurs within a context that executes system-level operations, the lack of input validation enables an unprivileged user to inject malicious payloads into the underlying operating system commands.
From a technical perspective, the flaw exploits the direct mapping between CLI inputs and backend script execution without adequate boundary checks. When a low-privileged user submits crafted data through this specific command interface, the Junos OS parser interprets these inputs as executable shell instructions rather than literal string values. This failure in input validation allows the attacker to break out of the intended application context and execute commands with root-level privileges. The consequence is a complete compromise of device integrity, as the attacker gains full control over the network infrastructure element, bypassing standard access controls designed to restrict low-privileged accounts from performing administrative tasks or modifying system configurations.
The operational impact of this vulnerability is severe due to its potential for privilege escalation and remote exploitation if combined with other vectors such as SSH or web management interfaces that allow local command execution. An attacker who gains a foothold on the device, even at a basic user level, can leverage this flaw to escalate privileges to root. This enables unauthorized access to sensitive system files, modification of security policies, installation of persistent backdoors, and potential pivoting into other segments of the network. The vulnerability undermines the fundamental principle of least privilege within Junos OS, effectively neutralizing the protective barriers intended for non-administrative users.
This issue impacts specific versions of Juniper Networks Junos OS that have not received the necessary patches to address this input validation deficiency. Affected releases include version 24.4 prior to update 24.4R2-S4, version 25.2 prior to update 25.2R2-S1, and version 25.4 prior to update 25.4R1-S3. Releases preceding the 24.4R1 baseline are not susceptible to this specific flaw, indicating that the vulnerability was introduced in later development cycles or feature sets associated with these major versions. Organizations running any of the affected software builds must treat this as a high-priority remediation item due to the ease of exploitation and the severity of the resulting compromise.
Mitigation strategies primarily involve upgrading Junos OS to one of the fixed releases mentioned above, which implement proper input sanitization for the 'request csds' command. In environments where immediate patching is not feasible, network segmentation should be enforced to restrict access to management interfaces from untrusted networks. Additionally, implementing strict role-based access control policies can limit the number of users with local CLI access, thereby reducing the attack surface. Monitoring logs for unusual command execution patterns or privilege escalation attempts may also aid in early detection of exploitation activities while remediation efforts are underway.
From a classification standpoint, this vulnerability aligns with CWE-78 Improper Neutralization of Special Elements used in an OS Command and is associated with ATT&CK technique T1059 Command and Scripting Interpreter for lateral movement or persistence after initial access. The scenario reflects common pitfalls in embedded system development where CLI parsing logic does not adequately separate data from executable code, leading to unintended command execution. Addressing this requires rigorous secure coding practices focused on input validation and the use of safe APIs that do not invoke shell interpreters directly with user-controlled arguments.