A Use After Free vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). In a Non Stop Routing (NSR) scenario, an unexpected kernel restart might be observed if bgp auto-discovery is enabled and if there is a BGP neighbor flap of auto-discovery sessions for any reason. This is a race condition which is outside of an attackers direct control and it depends on system internal timing whether this issue occurs. This issue affects Juniper Networks Junos OS Evolved: 21.3 versions prior to 21.3R3-EVO; 21.4 versions prior to 21.4R2-EVO; 22.1 versions prior to 22.1R2-EVO; 22.2 versions prior to 22.2R1-S1-EVO, 22.2R2-EVO.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Junos_os_evolved | Juniper | 21.3 (including) | 21.3 (including) |
| Junos_os_evolved | Juniper | 21.3-r1 (including) | 21.3-r1 (including) |
| Junos_os_evolved | Juniper | 21.3-r1-s1 (including) | 21.3-r1-s1 (including) |
| Junos_os_evolved | Juniper | 21.3-r2 (including) | 21.3-r2 (including) |
| Junos_os_evolved | Juniper | 21.3-r2-s1 (including) | 21.3-r2-s1 (including) |
| Junos_os_evolved | Juniper | 21.3-r2-s2 (including) | 21.3-r2-s2 (including) |
| Junos_os_evolved | Juniper | 21.4 (including) | 21.4 (including) |
| Junos_os_evolved | Juniper | 21.4-r1 (including) | 21.4-r1 (including) |
| Junos_os_evolved | Juniper | 21.4-r1-s1 (including) | 21.4-r1-s1 (including) |
| Junos_os_evolved | Juniper | 21.4-r1-s2 (including) | 21.4-r1-s2 (including) |
| Junos_os_evolved | Juniper | 22.1-r1 (including) | 22.1-r1 (including) |
| Junos_os_evolved | Juniper | 22.1-r1-s1 (including) | 22.1-r1-s1 (including) |
| Junos_os_evolved | Juniper | 22.1-r1-s2 (including) | 22.1-r1-s2 (including) |
| Junos_os_evolved | Juniper | 22.2-r1 (including) | 22.2-r1 (including) |