CVE-2014-6449 in Junos
Summary
by MITRE
Juniper Junos OS before 12.1X44-D50, 12.1X46 before 12.1X46-D35, 12.1X47 before 12.1X47-D25, 12.3 before 12.3R10, 12.3X48 before 12.3X48-D15, 13.2 before 13.2R8, 13.3 before 13.3R7, 14.1 before 14.1R5, and 14.2 before 14.2R1 do not properly handle TCP packet reassembly, which allows remote attackers to cause a denial of service (buffer consumption) via a crafted sequence of packets "destined to the device."
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Analysis
by VulDB Data Team • 06/22/2022
The vulnerability described in CVE-2014-6449 represents a critical buffer handling flaw within Juniper Junos OS network operating systems that affects multiple version branches spanning from 12.1X44-D50 through 14.2R1. This issue resides in the TCP packet reassembly mechanism, which is fundamental to network protocol processing and packet handling within the operating system. The flaw manifests when the system receives a crafted sequence of TCP packets specifically designed to exploit the buffer management implementation. According to industry standards, this vulnerability maps to CWE-129, which covers improper validation of array index values, and CWE-131, which addresses improper handling of buffer boundaries during memory operations. The attack vector is classified as remote, allowing adversaries to exploit this weakness from outside the network perimeter without requiring authentication or privileged access.
The technical implementation of this vulnerability stems from inadequate buffer management during TCP packet reassembly operations within the Junos OS kernel. When the system processes a sequence of TCP packets that contain overlapping or malformed segment information, the packet reassembly logic fails to properly validate the buffer boundaries and memory allocation parameters. This flaw causes the system to consume excessive buffer memory resources in a manner that leads to resource exhaustion, ultimately resulting in a denial of service condition. The specific nature of the attack involves sending carefully constructed TCP packets that trigger the buffer consumption behavior, causing legitimate network traffic to be disrupted or completely blocked. The operational impact extends beyond simple service interruption, as it can render network devices completely unresponsive to legitimate traffic while maintaining the ability to process the malicious packets that cause the resource exhaustion.
Network administrators and security professionals must understand that this vulnerability creates a significant operational risk for organizations relying on Juniper network infrastructure, particularly those with high-availability requirements or mission-critical network services. The attack can be executed remotely without authentication, making it particularly dangerous as it requires no insider knowledge or privileged access to exploit. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1498, which involves network denial of service attacks, and T1566, which covers social engineering through phishing or malicious network traffic. Organizations may experience cascading failures when this vulnerability is exploited, as network devices become unresponsive and can trigger failover mechanisms that disrupt network operations. The resource consumption pattern suggests that attackers can maintain the denial of service condition for extended periods, potentially leading to prolonged service degradation or complete network outages.
The recommended mitigations for CVE-2014-6449 involve immediate patching of affected Junos OS versions to the recommended secure releases that contain proper buffer validation and TCP reassembly logic. Organizations should also implement network segmentation and access controls to limit exposure to potentially malicious traffic sources. Monitoring and alerting systems should be configured to detect unusual packet patterns that may indicate exploitation attempts. Additionally, network administrators should consider implementing rate limiting and traffic filtering rules to prevent excessive packet processing that could trigger the vulnerability. The patching process requires careful planning and testing to ensure that security updates do not introduce compatibility issues with existing network configurations or applications. Organizations should also conduct vulnerability assessments to identify all affected devices within their network infrastructure and prioritize remediation based on risk exposure and business criticality.