CVE-2023-22400

An Uncontrolled Resource Consumption vulnerability in the PFE management daemon (evo-pfemand) of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause an FPC crash leading to a Denial of Service (DoS). When a specific SNMP GET operation or a specific CLI command is executed this will cause a GUID resource leak, eventually leading to exhaustion and result in an FPC crash and reboot. GUID exhaustion will trigger a syslog message like one of the following for example: evo-pfemand[]: get_next_guid: Ran out of Guid Space … evo-aftmand-zx[]: get_next_guid: Ran out of Guid Space … This leak can be monitored by running the following command and taking note of the value in the rightmost column labeled Guids: user@host> show platform application-info allocations app evo-pfemand | match IFDId|IFLId|Context Node Application Context Name Live Allocs Fails Guids re0 evo-pfemand net::juniper::interfaces::IFDId 0 3448 0 3448 re0 evo-pfemand net::juniper::interfaces::IFLId 0 561 0 561 user@host> show platform application-info allocations app evo-pfemand | match IFDId|IFLId|Context Node Application Context Name Live Allocs Fails Guids re0 evo-pfemand net::juniper::interfaces::IFDId 0 3784 0 3784 re0 evo-pfemand net::juniper::interfaces::IFLId 0 647 0 647 This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R3-S3-EVO; 21.1-EVO version 21.1R1-EVO and later versions; 21.2-EVO versions prior to 21.2R3-S4-EVO; 21.3-EVO version 21.3R1-EVO and later versions; 21.4-EVO versions prior to 21.4R2-EVO.

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/JSA70196