CVE-2018-0049 in Junos
Summary
by MITRE
A NULL Pointer Dereference vulnerability in Juniper Networks Junos OS allows an attacker to cause the Junos OS kernel to crash. Continued receipt of this specifically crafted malicious MPLS packet will cause a sustained Denial of Service condition. This issue require it to be received on an interface configured to receive this type of traffic. Affected releases are Juniper Networks Junos OS: 12.1X46 versions above and including 12.1X46-D76 prior to 12.1X46-D81 on SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 12.3R12-S10; 12.3X48 versions above and including 12.3X48-D66 prior to 12.3X48-D75 on SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 14.1X53-D47 on EX2200/VC, EX3200, EX3300/VC, EX4200, EX4300, EX4550/VC, EX4600, EX6200, EX8200/VC (XRE), QFX3500, QFX3600, QFX5100; 14.1X53 versions above and including 14.1X53-D115 prior to 14.1X53-D130 on QFabric System; 15.1 versions above and including 15.1F6-S10; 15.1R4-S9; 15.1R6-S6; 15.1 versions above and including 15.1R7 prior to 15.1R7-S2; 15.1X49 versions above and including 15.1X49-D131 prior to 15.1X49-D150 on SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 15.1X53 versions above 15.1X53-D233 prior to 15.1X53-D235 on QFX5200/QFX5110; 15.1X53 versions up to and including 15.1X53-D471 prior to 15.1X53-D590 on NFX150, NFX250; 15.1X53-D67 on QFX10000 Series; 15.1X53-D59 on EX2300/EX3400; 16.1 versions above and including 16.1R3-S8; 16.1 versions above and including 16.1R4-S9 prior to 16.1R4-S12; 16.1 versions above and including 16.1R5-S4; 16.1 versions above and including 16.1R6-S3 prior to 16.1R6-S6; 16.1 versions above and including 16.1R7 prior to 16.1R7-S2; 16.2 versions above and including 16.2R1-S6; 16.2 versions above and including 16.2R2-S5 prior to 16.2R2-S7; 17.1R1-S7; 17.1 versions above and including 17.1R2-S7 prior to 17.1R2-S9; 17.2R1-S6; 17.2 versions above and including 17.2R2-S4 prior to 17.2R2-S6; 17.2X75 versions above and including 17.2X75-D100 prior to X17.2X75-D101, 17.2X75-D110; 17.3 versions above and including 17.3R1-S4 on All non-SRX Series and SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 17.3 versions above and including 17.3R2-S2 prior to 17.3R2-S4 on All non-SRX Series and SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 17.3R3 on All non-SRX Series and SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 17.4 versions above and including 17.4R1-S3 prior to 17.4R1-S5 on All non-SRX Series and SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 17.4R2 on All non-SRX Series and SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 18.1 versions above and including 18.1R2 prior to 18.1R2-S3, 18.1R3 on All non-SRX Series and SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 18.2 versions above and including 18.2R1 prior to 18.2R1-S2, 18.2R1-S3, 18.2R2 on All non-SRX Series and SRX100, SRX110, SRX210, SRX220, SRX240m, SRX550m SRX650, SRX300, SRX320, SRX340, SRX345, SRX1500, SRX4100, SRX4200, SRX4600 and vSRX; 18.2X75 versions above and including 18.2X75-D5 prior to 18.2X75-D20.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/23/2023
The vulnerability described in CVE-2018-0049 represents a critical NULL pointer dereference issue within Juniper Networks Junos OS, specifically affecting multiple hardware platforms including SRX series firewalls, EX series switches, QFX series switches, and NFX series devices. This flaw manifests when the system processes specifically crafted MPLS packets, leading to a kernel crash that can be exploited to achieve sustained denial of service conditions. The vulnerability is particularly concerning because it requires no authentication or privilege escalation, making it accessible to any attacker who can send malicious packets to an affected interface. The technical root cause stems from improper validation of packet headers within the MPLS processing module, where a null pointer reference occurs when handling malformed MPLS labels, resulting in an immediate system crash. This behavior aligns with CWE-476, which defines NULL pointer dereference as a common weakness in software systems where a null pointer is dereferenced without proper validation.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged to create persistent denial of service conditions that may require manual intervention to restore system functionality. Network administrators face the challenge of identifying and mitigating this issue across multiple device types and software versions, with the affected releases spanning from older Junos OS versions through to more recent releases including 17.4R2 and 18.2R2. The vulnerability affects both physical and virtualized environments, including vSRX instances, indicating that the flaw exists at the core operating system level rather than being hardware-specific. Attackers can exploit this vulnerability by sending carefully constructed MPLS packets to interfaces configured to process such traffic, potentially causing cascading failures in network infrastructure that relies on these devices for traffic management and security enforcement. The attack surface is broad due to the numerous affected platforms, with the vulnerability impacting both edge and core network equipment, making it particularly dangerous in enterprise and service provider environments where these devices form critical infrastructure components.
Mitigation strategies for CVE-2018-0049 should focus on immediate patch deployment across all affected Junos OS versions, as provided by Juniper Networks in their security advisories. Network administrators should implement ingress filtering and packet inspection mechanisms to identify and block malicious MPLS traffic at network boundaries, reducing the risk of exploitation. Configuration changes such as disabling MPLS processing on interfaces where it is not required can serve as a temporary workaround while patches are deployed. The implementation of monitoring and alerting systems to detect unusual kernel crashes or restart patterns can help identify exploitation attempts. Additionally, organizations should conduct thorough vulnerability assessments to identify all affected devices within their network infrastructure and prioritize remediation efforts based on risk exposure. The vulnerability's characteristics align with ATT&CK technique T1499.002, which describes network denial of service attacks, and T1595.001, involving network infiltration through network devices, making it a significant concern for cybersecurity teams responsible for network infrastructure protection. Organizations should also consider implementing network segmentation to limit the impact of potential exploitation and ensure that critical network functions are not entirely dependent on vulnerable devices.