Denial of Service (DoS)

Affecting microsoft.aspnetcore.websockets package, versions [2.1.0,2.1.7) || [2.2.0,2.2.1)

Overview

Microsoft.AspNetCore.WebSockets is a ASP.NET Core web socket middleware for use on top of opaque servers.

Affected versions of this package are vulnerable to Denial of Service (DoS). If an application is hosted on Internet Information Server (IIS), a remote unauthenticated attacker can use a specially crafted request can cause a Denial of Service.

Details

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

Remediation

Upgrade Microsoft.AspNetCore.WebSockets to version 2.1.7, 2.2.1 or higher.

References

Do your applications use this vulnerable package?

CVSS Score

7.5
high severity
  • Attack Vector
    Network
  • Attack Complexity
    Low
  • Privileges Required
    None
  • User Interaction
    None
  • Scope
    Unchanged
  • Confidentiality
    None
  • Integrity
    None
  • Availability
    High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Credit
Unknown
CVE
CVE-2019-0548
CWE
CWE-400
Snyk ID
SNYK-DOTNET-MICROSOFTASPNETCOREWEBSOCKETS-72898
Disclosed
08 Jan, 2019
Published
10 Jan, 2019