On Juniper Networks Junos OS and Junos OS Evolved platforms with EVPN configured, receipt of specific BGP packets causes a slow memory leak. If the memory is exhausted the rpd process might crash. If the issue occurs, the memory leak could be seen by executing the show task memory detail | match policy | match evpn command multiple times to check if memory (Alloc Blocks value) is increasing. root@device> show task memory detail | match policy | match evpn ———————— Allocator Memory Report ———————— Name | Size | Alloc DTXP Size | Alloc Blocks | Alloc Bytes | MaxAlloc Blocks | MaxAlloc Bytes Policy EVPN Params 20 24 3330678 79936272 3330678 79936272 root@device> show task memory detail | match policy | match evpn ———————— Allocator Memory Report ———————— Name | Size | Alloc DTXP Size | Alloc Blocks | Alloc Bytes | MaxAlloc Blocks | MaxAlloc Bytes Policy EVPN Params 20 24 36620255 878886120 36620255 878886120 This issue affects: Juniper Networks Junos OS 19.4 versions prior to 19.4R2; 20.1 versions prior to 20.1R1-S4, 20.1R2; Juniper Networks Junos OS Evolved: 19.4 versions; 20.1 versions prior to 20.1R1-S4-EVO, 20.1R2-EVO; 20.2 versions prior to 20.2R1-EVO; This issue does not affect: Juniper Networks Junos OS releases prior to 19.4R1. Juniper Networks Junos OS Evolved releases prior to 19.4R1-EVO.
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.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Junos | Juniper | 19.4-r1 (including) | 19.4-r1 (including) |
| Junos | Juniper | 19.4-r1-s1 (including) | 19.4-r1-s1 (including) |
| Junos | Juniper | 19.4-r1-s2 (including) | 19.4-r1-s2 (including) |
| Junos | Juniper | 20.1-r1 (including) | 20.1-r1 (including) |
| Junos | Juniper | 20.1-r1-s1 (including) | 20.1-r1-s1 (including) |
| Junos | Juniper | 20.1-r1-s2 (including) | 20.1-r1-s2 (including) |
| Junos | Juniper | 20.1-r1-s3 (including) | 20.1-r1-s3 (including) |
| Junos_os_evolved | Juniper | 19.4-r1 (including) | 19.4-r1 (including) |
| Junos_os_evolved | Juniper | 19.4-r2 (including) | 19.4-r2 (including) |
| Junos_os_evolved | Juniper | 19.4-r2-s1 (including) | 19.4-r2-s1 (including) |
| Junos_os_evolved | Juniper | 20.1 (including) | 20.1 (including) |
| Junos_os_evolved | Juniper | 20.1-r1 (including) | 20.1-r1 (including) |
| Junos_os_evolved | Juniper | 20.2 (including) | 20.2 (including) |
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:
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.