CVE-2022-22155

An Uncontrolled Resource Consumption vulnerability in the handling of IPv6 neighbor state change events in Juniper Networks Junos OS allows an adjacent attacker to cause a memory leak in the Flexible PIC Concentrator (FPC) of an ACX5448 router. The continuous flapping of an IPv6 neighbor with specific timing will cause the FPC to run out of resources, leading to a Denial of Service (DoS) condition. Once the condition occurs, further packet processing will be impacted, creating a sustained Denial of Service (DoS) condition, requiring a manual PFE restart to restore service. The following error messages will be seen after the FPC resources have been exhausted: fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 This issue only affects the ACX5448 router. No other products or platforms are affected by this vulnerability. This issue affects Juniper Networks Junos OS on ACX5448: 18.4 versions prior to 18.4R3-S10; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R1-S8, 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2.

Weakness

The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

Affected Software

Extended Description

Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system. There are at least three distinct scenarios which can commonly lead to resource exhaustion:

Resource exhaustion problems are often result due to an incorrect implementation of the following situations:

Potential Mitigations

• Mitigation of resource exhaustion attacks requires that the target system either:

• The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

• The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/147.html
• https://cwe.mitre.org/data/definitions/227.html
• https://cwe.mitre.org/data/definitions/492.html

References

• https://kb.juniper.net/JSA11263
• https://kb.juniper.net/JSA11263