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.
| 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) |
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.