Suricata is a network IDS, IPS and NSM engine. Prior to versions 8.0.3 and 7.0.14, crafted DCERPC traffic can cause Suricata to expand a buffer w/o limits, leading to memory exhaustion and the process getting killed. While reported for DCERPC over UDP, it is believed that DCERPC over TCP and SMB are also vulnerable. DCERPC/TCP in the default configuration should not be vulnerable as the default stream depth is limited to 1MiB. Versions 8.0.3 and 7.0.14 contain a patch. Some workarounds are available. For DCERPC/UDP, disable the parser. For DCERPC/TCP, the stream.reassembly.depth setting will limit the amount of data that can be buffered. For DCERPC/SMB, the stream.reassembly.depth can be used as well, but is set to unlimited by default. Imposing a limit here may lead to loss of visibility in SMB.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Suricata | Oisf | * | 7.0.14 (excluding) |
| Suricata | Oisf | 8.0.0 (including) | 8.0.3 (excluding) |
| Suricata | Ubuntu | upstream | * |
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