CVE-2023-44191 in Junos OS
Summary
by MITRE • 10/25/2023
An Allocation of Resources Without Limits or Throttling vulnerability in Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS).
On all Junos OS QFX5000 Series and EX4000 Series platforms, when a high number of VLANs are configured, a specific DHCP packet will cause PFE hogging which will lead to dropping of socket connections.
This issue affects:
Juniper Networks Junos OS on QFX5000 Series and EX4000 Series
* 21.1 versions prior to 21.1R3-S5; * 21.2 versions prior to 21.2R3-S5; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S1; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2.
This issue does not affect Juniper Networks Junos OS versions prior to 21.1R1
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Analysis
by VulDB Data Team • 10/25/2023
This vulnerability represents a critical resource allocation flaw in Juniper Networks Junos OS affecting specific hardware platforms including QFX5000 and EX4000 series devices. The issue manifests as an allocation of resources without proper limits or throttling mechanisms, creating a pathway for unauthenticated network-based attackers to execute denial of service attacks. The vulnerability specifically targets environments with high VLAN configurations where certain DHCP packets trigger PFE (Packet Forwarding Engine) hogging behavior that ultimately results in socket connection drops and service disruption.
The technical implementation of this vulnerability stems from insufficient resource management within the DHCP processing pipeline of the affected Junos OS versions. When multiple VLANs are configured on these platforms, a specially crafted DHCP packet can cause the PFE to consume excessive processing resources without proper throttling controls. This resource exhaustion leads to the system's inability to maintain established socket connections, effectively creating a denial of service condition that impacts network availability and connectivity for legitimate users.
From an operational impact perspective, this vulnerability poses significant risk to network infrastructure reliability and business continuity. Organizations utilizing affected Junos OS versions on QFX5000 and EX4000 platforms face potential service disruption that could affect critical network operations, particularly in environments with extensive VLAN deployments. The vulnerability's exploitation requires only network-based access without authentication credentials, making it particularly dangerous as attackers can leverage this weakness from external network positions. The specific PFE hogging behavior suggests that the attack can be executed with relatively minimal resources, potentially allowing for rapid service degradation.
The vulnerability aligns with CWE-770, which describes allocation of resources without limits or throttling, and represents a clear violation of secure coding practices that should prevent unbounded resource consumption. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network disruption via resource exhaustion, and T1566.002, which involves spearphishing with social engineering techniques to gain initial access. Organizations should implement immediate mitigations including applying the relevant Juniper security patches for all affected versions, implementing network segmentation to limit exposure, and monitoring for anomalous DHCP traffic patterns that may indicate exploitation attempts. The affected versions span multiple release branches, requiring comprehensive vulnerability assessment and patch management across all impacted network infrastructure components.