CVE-2018-0001 in Junos
Summary
by MITRE
A remote, unauthenticated attacker may be able to execute code by exploiting a use-after-free defect found in older versions of PHP through injection of crafted data via specific PHP URLs within the context of the J-Web process. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D67; 12.3 versions prior to 12.3R12-S5; 12.3X48 versions prior to 12.3X48-D35; 14.1 versions prior to 14.1R8-S5, 14.1R9; 14.1X53 versions prior to 14.1X53-D44, 14.1X53-D50; 14.2 versions prior to 14.2R7-S7, 14.2R8; 15.1 versions prior to 15.1R3; 15.1X49 versions prior to 15.1X49-D30; 15.1X53 versions prior to 15.1X53-D70.
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Analysis
by VulDB Data Team • 01/20/2023
This vulnerability represents a critical use-after-free flaw in the PHP interpreter component of Juniper Networks Junos OS operating systems. The defect occurs when the J-Web web interface processes specific PHP URLs containing crafted data, creating conditions where freed memory locations can be accessed and potentially overwritten by malicious input. Such vulnerabilities are particularly dangerous because they can be exploited remotely without authentication, allowing attackers to execute arbitrary code on affected systems. The vulnerability stems from improper memory management practices where PHP objects are freed from memory but references to them persist, creating opportunities for attackers to manipulate the freed memory space.
The technical exploitation of this vulnerability follows a classic use-after-free attack pattern that aligns with CWE-416, which specifically addresses the use of freed memory conditions. When the J-Web process handles malicious PHP input through web requests, it triggers a sequence where memory allocated to PHP objects is released but not properly invalidated. Attackers can then inject specially crafted data that, when processed by the vulnerable PHP interpreter, causes the system to execute code in the context of the J-Web process. This process typically involves manipulating memory layout and exploiting the timing window between object deallocation and subsequent reuse, allowing for code execution with the privileges of the web server process.
The operational impact of this vulnerability is severe for network infrastructure devices running affected Junos OS versions. Since the exploit requires no authentication and can be executed remotely, it provides attackers with unrestricted access to the affected network devices. This capability enables comprehensive compromise of network security controls, including potential privilege escalation to root-level access, data exfiltration, and disruption of network services. The vulnerability affects multiple major release branches of Junos OS, indicating a widespread exposure across different network device models and deployment scenarios. Organizations running these vulnerable versions face significant risk of unauthorized access to their network infrastructure, potentially leading to complete network compromise and data breaches.
Organizations should implement immediate mitigations including applying the relevant security patches provided by Juniper Networks, which address the memory management issues in the PHP interpreter component. Network segmentation and access control measures should be strengthened to limit exposure of affected devices to untrusted networks. Monitoring for suspicious web traffic patterns and anomalous access attempts to J-Web interfaces should be enhanced through security information and event management systems. Additionally, implementing network-based intrusion detection systems with signatures for known exploit patterns can help detect exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1059.007 for remote code execution via web services, making it a high-priority target for security teams implementing threat hunting and incident response procedures. Regular vulnerability assessments and patch management programs should be enforced to prevent similar issues in other components of the network infrastructure.