CVE-2018-0059 in ScreenOS
Summary
by MITRE
A persistent cross-site scripting vulnerability in the graphical user interface of ScreenOS may allow a remote authenticated user to inject web script or HTML and steal sensitive data and credentials from a web administration session, possibly tricking a follow-on administrative user to perform administrative actions on the device. Affected releases are Juniper Networks ScreenOS 6.3.0 versions prior to 6.3.0r26.
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Analysis
by VulDB Data Team • 05/25/2023
The vulnerability identified as CVE-2018-0059 represents a critical persistent cross-site scripting flaw within the graphical user interface of Juniper Networks ScreenOS operating systems. This security weakness exists in the web administration interface component of the network security platform, specifically affecting versions prior to 6.3.0r26. The vulnerability stems from inadequate input validation and output encoding mechanisms within the web interface, allowing malicious actors to inject malicious scripts that persist in the system's user interface elements. Such a flaw fundamentally compromises the integrity of the administrative session management and user trust within the network security infrastructure.
The technical implementation of this vulnerability involves the failure to properly sanitize user-supplied input within the web administration interface of ScreenOS devices. When authenticated users interact with the graphical interface, the system does not adequately filter or encode special characters and script tags that could be embedded in input fields or parameters. This allows an authenticated attacker to inject malicious JavaScript code or HTML content that gets stored within the system and subsequently executed in the context of other administrative sessions. The persistence aspect of this vulnerability means that the injected code remains active even after the initial injection point, making it particularly dangerous for long-term attacks. This flaw aligns with CWE-79 which specifically addresses cross-site scripting vulnerabilities where improper validation of input allows malicious scripts to be executed in the victim's browser context.
The operational impact of CVE-2018-0059 extends far beyond simple data theft, creating a comprehensive attack vector that can compromise entire network security infrastructures. An attacker who successfully exploits this vulnerability can steal administrative credentials, session tokens, and sensitive configuration data from active web administration sessions. The persistent nature of the vulnerability allows for extended attack windows where malicious code can remain undetected while collecting information over time. Furthermore, the vulnerability can be leveraged to trick subsequent administrative users into performing unauthorized actions on the device, effectively enabling privilege escalation attacks that could lead to complete device compromise. This type of attack directly violates the principle of least privilege and can result in unauthorized network access, configuration changes, and potential data exfiltration. The attack vector operates through the standard web administration interface, making it accessible to attackers who can authenticate to the system with valid credentials.
Organizations affected by this vulnerability face significant risks including potential unauthorized access to critical network infrastructure, data breaches, and operational disruption. The impact is particularly severe for enterprises that rely heavily on Juniper ScreenOS devices for network security, as these systems often serve as gateways protecting sensitive network resources. The vulnerability can be exploited by attackers who have gained legitimate administrative credentials through various means such as credential theft, social engineering, or other initial compromise techniques. Security teams must consider this vulnerability in the context of the broader attack surface and potential lateral movement opportunities it provides. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access and privilege escalation, specifically targeting the web application layer of network security infrastructure. The vulnerability also relates to the persistence and privilege escalation tactics that attackers use to maintain access to compromised systems over extended periods.
Mitigation strategies for CVE-2018-0059 require immediate implementation of the vendor-provided security patches and updates. Organizations should prioritize upgrading all affected ScreenOS devices to version 6.3.0r26 or later, which contains the necessary fixes for the cross-site scripting vulnerability. Network administrators should also implement additional monitoring measures to detect unusual administrative activities that might indicate exploitation attempts. Configuration reviews should include verification of proper input validation settings and output encoding mechanisms within the web interface. Regular security assessments and penetration testing of the web administration interfaces should be conducted to identify similar vulnerabilities. The remediation process should also include user education about the risks of clicking on suspicious links or entering untrusted input in administrative interfaces, as social engineering remains a common initial compromise technique for gaining access to administrative accounts. Security monitoring should specifically focus on identifying anomalous session behavior and unexpected administrative actions that could indicate exploitation of this vulnerability.