Denial of Service (DoS) The advisory has been revoked - it doesn't affect any version of package openvpn_access_server  (opens in a new tab)


Threat Intelligence

EPSS
1.28% (69th percentile)

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  • Snyk IDSNYK-UNMANAGED-OPENVPNACCESSSERVER-2383239
  • published26 Jan 2022
  • disclosed4 May 2020
  • creditUnknown

Introduced: 4 May 2020

CVE-2020-11462  (opens in a new tab)
CWE-776  (opens in a new tab)

How to fix?

Upgrade openvpn_access_server to version 2.7.0, 2.8.3 or higher.

Amendment

This was deemed not a vulnerability.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS). An issue was discovered in OpenVPN Access Server before 2.7.0 and 2.8.x before 2.8.3. With the full featured RPC2 interface enabled, it is possible to achieve a temporary DoS state of the management interface when sending an XML Entity Expansion (XEE) payload to the XMLRPC based RPC2 interface. The duration of the DoS state depends on available memory and CPU speed. The default restricted mode of the RPC2 interface is NOT vulnerable.

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

References