CVE-2017-2312 in Junos
Summary
by MITRE
On Juniper Networks devices running Junos OS affected versions and with LDP enabled, a specific LDP packet destined to the RE (Routing Engine) will consume a small amount of the memory allocated for the rpd (routing protocol daemon) process. Over time, repeatedly receiving this type of LDP packet(s) will cause the memory to exhaust and the rpd process to crash and restart. It is not possible to free up the memory that has been consumed without restarting the rpd process. This issue affects Junos OS based devices with either IPv4 or IPv6 LDP enabled via the [protocols ldp] configuration (the native IPv6 support for LDP is available in Junos OS 16.1 and higher). The interface on which the packet arrives needs to have LDP enabled. The affected Junos versions are: 13.3 prior to 13.3R10; 14.1 prior to 14.1R8; 14.2 prior to 14.2R7-S6 or 14.2R8; 15.1 prior to 15.1F2-S14, 15.1F6-S4, 15.1F7, 15.1R4-S7, 15.1R5; 15.1X49 before 15.1X49-D70; 15.1X53 before 15.1X53-D230, 15.1X53-D63, 15.1X53-D70; 16.1 before 16.1R2. 16.2R1 and all subsequent releases have a resolution for this vulnerability.
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Analysis
by VulDB Data Team • 12/21/2020
This vulnerability represents a memory exhaustion issue within the routing protocol daemon process on Juniper Networks devices running affected versions of Junos OS. The flaw specifically impacts devices with LDP (Label Distribution Protocol) enabled, where maliciously crafted LDP packets can trigger memory consumption within the rpd process that cannot be reclaimed without a process restart. The vulnerability operates through a gradual memory leak mechanism that accumulates over time, ultimately leading to process crashes and system instability. This represents a classic denial of service vulnerability that can be exploited to disrupt network routing operations and potentially cause service interruptions across affected networks.
The technical implementation of this vulnerability stems from improper memory management within the LDP packet processing logic of the routing protocol daemon. When specific LDP packets are received by the Routing Engine through interfaces with LDP enabled, the system allocates memory for processing these packets but fails to properly release this memory back to the system. The memory consumption occurs incrementally with each packet received, creating a cumulative effect that eventually exhausts available memory resources. This memory leak pattern aligns with CWE-401, which describes improper handling of memory allocation and deallocation in software systems. The vulnerability specifically targets the rpd process, which is responsible for routing protocol operations and maintaining routing tables within Junos OS environments.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network stability and availability. Network administrators may experience unexpected routing engine restarts, leading to temporary loss of routing services and potential disruption of network connectivity. The issue affects a broad range of Junos OS versions across multiple release branches, indicating a widespread exposure that would impact various network deployments including enterprise, service provider, and data center environments. The vulnerability is particularly concerning because it can be exploited remotely through network traffic without requiring authentication, making it a significant risk for networks with exposed routing protocols. This aligns with ATT&CK technique T1499.004, which covers resource exhaustion attacks targeting network infrastructure components.
Mitigation strategies for this vulnerability require immediate implementation of firmware upgrades to versions 16.2R1 or later where the issue has been resolved. Network administrators should also consider implementing traffic filtering rules to restrict LDP packet traffic to only necessary interfaces and reduce exposure risk. The recommended approach involves disabling LDP on interfaces where it is not required, particularly in environments where the protocol is not actively used for MPLS operations. Additionally, monitoring systems should be implemented to detect unusual memory consumption patterns in routing protocol processes, which could indicate exploitation attempts. Organizations should also conduct thorough vulnerability assessments to identify all affected devices within their network infrastructure and prioritize remediation efforts based on network criticality and exposure levels. The vulnerability demonstrates the importance of proper memory management in network operating systems and highlights the need for comprehensive security testing of routing protocols in production environments.