CVE-2015-5360 in Junos
Summary
by MITRE
IPv6 sendd in Juniper Junos 12.1X44 before 12.1X44-D51, 12.1X46 before 12.1X46-D36, 12.1X46 before 12.1X46-D40, 12.1X47 before 12.1X47-D25, 12.3 before 12.3R10, 12.3X48 before 12.3X48-D20, 13.2 before 13.2R8, 13.3 before 13.3R6, 14.1 before 14.1R5, 14.2 before 14.2R3, 15.1 before 15.1R1, and 15.1X49 before 15.1X49-D20, when the "set protocols neighbor-discovery secure security-level default" option is configured, allows remote attackers to cause a denial of service (CPU consumption) via a crafted Secure Neighbor Discovery (SEND) Protocol packet.
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Analysis
by VulDB Data Team • 11/23/2024
The vulnerability described in CVE-2015-5360 represents a critical denial of service flaw within Juniper Junos operating system versions that implement the Secure Neighbor Discovery (SEND) protocol functionality. This issue specifically affects systems configured with the "set protocols neighbor-discovery secure security-level default" command, which enables secure neighbor discovery mechanisms designed to prevent unauthorized network access and maintain network integrity. The flaw manifests when these systems receive specially crafted SEND protocol packets that trigger excessive CPU processing demands, ultimately leading to system performance degradation and potential complete service unavailability.
The technical root cause of this vulnerability lies in the insufficient validation and processing logic within the IPv6 neighbor discovery implementation of Junos software. When a device with SEND enabled receives malformed or crafted neighbor discovery packets, the system's processing routines fail to properly handle the unexpected packet structures, causing the CPU to consume excessive resources in attempting to process these invalid communications. This behavior aligns with CWE-129, which describes improper validation of input boundaries, and CWE-400, which addresses unchecked resource consumption. The vulnerability specifically targets the neighbor discovery protocol implementation, which falls under the broader category of network protocol processing flaws that can be exploited for resource exhaustion attacks.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire network infrastructures. Network devices configured with SEND security features become vulnerable to attacks that can cause sustained CPU utilization near 100%, effectively rendering the device incapable of processing legitimate network traffic. This creates a cascading effect where network connectivity is severely degraded or completely lost, particularly in environments where multiple devices are configured with the vulnerable SEND settings. Attackers can exploit this vulnerability without requiring authentication credentials, making it particularly dangerous as it allows for unauthorized service disruption attacks that can be executed from external network positions.
Mitigation strategies for CVE-2015-5360 should prioritize immediate software updates to the affected Junos versions, with the specific patch releases mentioned in the CVE description providing the necessary fixes. Organizations should implement network segmentation to limit exposure of vulnerable devices and consider temporarily disabling SEND functionality where possible while patches are deployed. Network monitoring should be enhanced to detect unusual CPU consumption patterns that may indicate exploitation attempts, and baseline performance metrics should be established to quickly identify abnormal behavior. The ATT&CK framework categorizes this vulnerability under T1499.004 for Network Denial of Service, with potential lateral movement implications if attackers can use the service disruption to gain further network access. Additionally, implementing ingress filtering and access control lists to restrict neighbor discovery protocol traffic can provide additional defensive layers against exploitation attempts.