Any Juniper Networks SRX series device with one or more ALGs enabled may experience a flowd crash when traffic is processed by the Sun/MS-RPC ALGs. This vulnerability in the Sun/MS-RPC ALG services component of Junos OS allows an attacker to cause a repeated denial of service against the target. Repeated traffic in a cluster may cause repeated flip-flop failure operations or full failure to the flowd daemon halting traffic on all nodes. Only IPv6 traffic is affected by this issue. IPv4 traffic is unaffected. This issues is not seen with to-host traffic. This issue has no relation with HA services themselves, only the ALG service. No other Juniper Networks products or platforms are affected by this issue. Affected releases are Juniper Networks Junos OS 12.1X46 prior to 12.1X46-D55 on SRX; 12.1X47 prior to 12.1X47-D45 on SRX; 12.3X48 prior to 12.3X48-D32, 12.3X48-D35 on SRX; 15.1X49 prior to 15.1X49-D60 on SRX.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Junos | Juniper | 12.1x46 (including) | 12.1x46 (including) |
| Junos | Juniper | 12.1x46-d10 (including) | 12.1x46-d10 (including) |
| Junos | Juniper | 12.1x46-d15 (including) | 12.1x46-d15 (including) |
| Junos | Juniper | 12.1x46-d20 (including) | 12.1x46-d20 (including) |
| Junos | Juniper | 12.1x46-d25 (including) | 12.1x46-d25 (including) |
| Junos | Juniper | 12.1x46-d30 (including) | 12.1x46-d30 (including) |
| Junos | Juniper | 12.1x46-d35 (including) | 12.1x46-d35 (including) |
| Junos | Juniper | 12.1x46-d40 (including) | 12.1x46-d40 (including) |
| Junos | Juniper | 12.1x46-d45 (including) | 12.1x46-d45 (including) |
| Junos | Juniper | 12.1x46-d50 (including) | 12.1x46-d50 (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.