CVE-2018-0043 in Junos
Summary
by MITRE
Receipt of a specific MPLS packet may cause the routing protocol daemon (RPD) process to crash and restart or may lead to remote code execution. By continuously sending specific MPLS packets, an attacker can repeatedly crash the RPD process causing a sustained Denial of Service. This issue affects both IPv4 and IPv6. This issue can only be exploited from within the MPLS domain. End-users connected to the CE device cannot cause this crash. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D77 on SRX Series; 12.3 versions prior to 12.3R12-S10; 12.3X48 versions prior to 12.3X48-D75 on SRX Series; 14.1X53 versions prior to 14.1X53-D47 on QFX/EX Series; 14.1X53 versions prior to 14.1X53-D130 on QFabric Series; 15.1F6 versions prior to 15.1F6-S10; 15.1 versions prior to 15.1R4-S9 15.1R7; 15.1X49 versions prior to 15.1X49-D140 on SRX Series; 15.1X53 versions prior to 15.1X53-D59 on EX2300/EX3400 Series; 15.1X53 versions prior to 15.1X53-D67 on QFX10K Series; 15.1X53 versions prior to 15.1X53-D233 on QFX5200/QFX5110 Series; 15.1X53 versions prior to 15.1X53-D471 15.1X53-D490 on NFX Series; 16.1 versions prior to 16.1R3-S8 16.1R4-S8 16.1R5-S4 16.1R6-S4 16.1R7; 16.1X65 versions prior to 16.1X65-D48; 16.2 versions prior to 16.2R1-S6 16.2R3; 17.1 versions prior to 17.1R1-S7 17.1R2-S6 17.1R3; 17.2 versions prior to 17.2R1-S6 17.2R2-S3 17.2R3; 17.2X75 versions prior to 17.2X75-D100 17.2X75-D42 17.2X75-D91; 17.3 versions prior to 17.3R1-S4 17.3R2-S2 17.3R3; 17.4 versions prior to 17.4R1-S3 17.4R2 . No other Juniper Networks products or platforms are affected by this issue.
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Analysis
by VulDB Data Team • 05/23/2023
The vulnerability described in CVE-2018-0043 represents a critical flaw in Juniper Networks Junos OS routing protocol daemon RPD that manifests through malformed MPLS packets. This issue stems from insufficient input validation within the MPLS processing subsystem of the routing daemon, creating a condition where specially crafted packets can trigger memory corruption or unexpected behavior leading to process termination. The vulnerability operates at the network protocol level and specifically targets the Multiprotocol Label Switching implementation within Juniper's routing infrastructure, making it particularly dangerous for network devices that rely on MPLS for traffic engineering and quality of service management.
The technical exploitation of this vulnerability requires an attacker to be positioned within the MPLS domain, meaning they must have network access to the MPLS network segment where the vulnerable device operates. This constraint places the attack vector within the context of network infrastructure rather than external network access, though it still represents a significant security risk since MPLS domains often contain sensitive network traffic and critical infrastructure components. The vulnerability affects multiple product lines including SRX Series firewalls, QFX/EX Series switches, QFabric Series, and various NFX Series devices, indicating a widespread impact across Juniper's routing portfolio.
From an operational impact perspective, this vulnerability enables both denial of service and potential remote code execution scenarios. The most immediate threat manifests as a sustained denial of service attack where continuous injection of malformed MPLS packets causes the RPD process to repeatedly crash and restart, effectively disrupting network routing functionality and potentially causing network partitions or service degradation. The potential for remote code execution adds an additional layer of severity, as successful exploitation could allow an attacker to gain unauthorized control over the affected network device, potentially leading to complete network compromise. This vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1059 for command and control through network infrastructure manipulation.
The remediation strategy for this vulnerability requires immediate deployment of Juniper's security patches and software updates for all affected Junos OS versions across the identified product lines. Network administrators should prioritize patching of critical network infrastructure devices that operate within MPLS domains, particularly those serving as core routing points or edge devices handling MPLS traffic. Additionally, network segmentation and access control measures should be implemented to limit the potential attack surface by restricting MPLS domain access to authorized network entities only. Organizations should also consider implementing network monitoring solutions capable of detecting abnormal packet patterns or RPD process restarts that could indicate exploitation attempts. The vulnerability's requirement for internal MPLS domain access means that perimeter security measures alone may not be sufficient, requiring a comprehensive approach that includes both network access controls and proper software maintenance procedures to ensure all network devices remain patched against known vulnerabilities.