CVE-2020-1630 in Junos
Summary
by MITRE
A privilege escalation vulnerability in Juniper Networks Junos OS devices configured with dual Routing Engines (RE), Virtual Chassis (VC) or high-availability cluster may allow a local authenticated low-privileged user with access to the shell to perform unauthorized configuration modification. This issue does not affect Junos OS device with single RE or stand-alone configuration. This issue affects Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S14; 12.3X48 versions prior to 12.3X48-D86, 12.3X48-D90; 14.1X53 versions prior to 14.1X53-D51; 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D181, 15.1X49-D190; 15.1X49 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R4-S13, 16.1R7-S6; 16.2 versions prior to 16.2R2-S10; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R1-S9, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S6, 17.4R3; 18.1 versions prior to 18.1R3-S7; 18.2 versions prior to 18.2R2-S5, 18.2R3-S1; 18.2 versions prior to 18.2X75-D12, 18.2X75-D33, 18.2X75-D420, 18.2X75-D60, 18.2X75-D411; 18.3 versions prior to 18.3R1-S5, 18.3R2-S1, 18.3R3; 18.4 versions prior to 18.4R1-S4, 18.4R2-S1, 18.4R3; 19.1 versions prior to 19.1R1-S2, 19.1R2; 19.2 versions prior to 19.2R1-S1, 19.2R2.
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Analysis
by VulDB Data Team • 05/17/2024
This privilege escalation vulnerability in Juniper Networks Junos OS affects devices configured with dual Routing Engines, Virtual Chassis, or high-availability clusters, creating a critical security gap that allows low-privileged authenticated users to gain unauthorized access to configuration modification capabilities. The flaw specifically targets the inter-RE communication mechanisms and cluster synchronization processes that are fundamental to high-availability configurations, where the privilege separation between the primary and backup routing engines is insufficiently enforced. This vulnerability operates at the system level and directly impacts the integrity of configuration management processes that ensure consistency across redundant components, making it particularly dangerous in enterprise network environments where high availability is critical for business continuity.
The technical root cause of this vulnerability lies in improper privilege validation within the Junos OS kernel and configuration management subsystems when handling cross-replica operations in clustered environments. When a local authenticated user accesses the shell on a dual-RE device, the system fails to properly validate the user's privileges before allowing configuration modifications that should only be accessible to administrative users. This flaw is classified as a privilege escalation vulnerability under CWE-269, specifically related to insufficient privilege checks in multi-RE systems. The vulnerability exploits the trust relationship between routing engines in high-availability configurations, where the backup engine's access controls are not properly enforced when processing configuration changes initiated from the primary engine, creating an attack surface that allows privilege elevation through shell access.
The operational impact of this vulnerability extends beyond simple unauthorized configuration changes, potentially enabling attackers to manipulate routing policies, modify security settings, or redirect network traffic flows. In enterprise environments, this could lead to complete network compromise, as attackers could modify routing tables to intercept traffic, disable security features, or create backdoors for persistent access. The vulnerability affects multiple Junos OS versions across different release series, indicating a widespread issue that spans over a decade of product development and highlighting the persistence of privilege validation flaws in complex multi-engine systems. Network administrators face significant challenges in identifying affected devices, as the vulnerability only manifests in specific hardware configurations and requires a local authenticated user with shell access to exploit, but the consequences can be devastating for network security posture.
Mitigation strategies should focus on immediate patching of affected Junos OS versions, with particular attention to the specific release numbers mentioned in the vulnerability description. Organizations must also implement strict access controls and monitoring of shell access to minimize the attack surface, as the vulnerability requires local authenticated access to exploit. Network segmentation and least-privilege principles should be enforced to limit the potential impact of compromised accounts, while regular security audits of high-availability configurations should be conducted to identify and remediate similar issues. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the T1068 privilege escalation method, and organizations should consider this when developing their incident response procedures and security monitoring capabilities. Additionally, Juniper's official security advisories should be consulted for detailed patch information and implementation guidance, as the vulnerability affects critical network infrastructure components that require careful handling during remediation activities.