WordPress CVE-2019-20042 HTML Injection Vulnerability

Description

WordPress is prone to an HTML injection vulnerability. Successful exploits will allow attacker-supplied HTML and script code to run in the context of the affected browser, potentially allowing the attacker to steal cookie-based authentication credentials or to control how the site is rendered to the user. Other attacks are also possible.

Technologies Affected

• WordPress WordPress 0.71.0
• WordPress WordPress 1.0.1
• WordPress WordPress 1.0.2
• WordPress WordPress 1.1.1
• WordPress WordPress 1.2.0
• WordPress WordPress 1.2.1
• WordPress WordPress 1.2.2
• WordPress WordPress 1.2.3
• WordPress WordPress 1.2.5
• WordPress WordPress 1.3
• WordPress WordPress 1.3.1
• WordPress WordPress 1.3.3
• WordPress WordPress 1.4
• WordPress WordPress 1.5
• WordPress WordPress 1.5.0
• WordPress WordPress 1.5.1 .2
• WordPress WordPress 1.5.1 .3
• WordPress WordPress 1.5.1
• WordPress WordPress 1.5.1.1
• WordPress WordPress 1.5.2
• WordPress WordPress 1.6
• WordPress WordPress 1.6.2
• WordPress WordPress 2.0.0
• WordPress WordPress 2.0.1
• WordPress WordPress 2.0.10
• WordPress WordPress 2.0.11
• WordPress WordPress 2.0.2
• WordPress WordPress 2.0.3
• WordPress WordPress 2.0.4
• WordPress WordPress 2.0.5
• WordPress WordPress 2.0.6
• WordPress WordPress 2.0.7
• WordPress WordPress 2.0.9
• WordPress WordPress 2.1.1
• WordPress WordPress 2.1.2
• WordPress WordPress 2.1.3
• WordPress WordPress 2.2
• WordPress WordPress 2.8.6
• WordPress WordPress 2.9
• WordPress WordPress 2.9.1
• WordPress WordPress 2.9.1.1
• WordPress WordPress 3.0.1
• WordPress WordPress 3.0.2
• WordPress WordPress 3.0.3
• WordPress WordPress 3.0.4
• WordPress WordPress 3.0.5
• WordPress WordPress 3.0.6
• WordPress WordPress 3.1
• WordPress WordPress 3.1.1
• WordPress WordPress 3.1.2
• WordPress WordPress 3.1.3
• WordPress WordPress 3.1.4
• WordPress WordPress 3.2
• WordPress WordPress 3.3
• WordPress WordPress 3.3.1
• WordPress WordPress 3.3.2
• WordPress WordPress 3.3.3
• WordPress WordPress 3.4
• WordPress WordPress 3.4.0
• WordPress WordPress 3.4.1
• WordPress WordPress 3.4.2
• WordPress WordPress 3.5
• WordPress WordPress 3.5.0
• WordPress WordPress 3.5.1
• WordPress WordPress 3.5.2
• WordPress WordPress 3.6
• WordPress WordPress 3.6.0
• WordPress WordPress 3.6.1
• WordPress WordPress 3.7
• WordPress WordPress 3.7.1
• WordPress WordPress 3.7.4
• WordPress WordPress 3.7.5
• WordPress WordPress 3.8
• WordPress WordPress 3.8.1
• WordPress WordPress 3.8.2
• WordPress WordPress 3.8.3
• WordPress WordPress 3.8.4
• WordPress WordPress 3.8.5
• WordPress WordPress 3.9
• WordPress WordPress 3.9.0
• WordPress WordPress 3.9.1
• WordPress WordPress 3.9.2
• WordPress WordPress 3.9.3
• WordPress WordPress 4.0
• WordPress WordPress 4.0.1
• WordPress WordPress 4.1.0
• WordPress WordPress 4.1.1
• WordPress WordPress 4.1.2
• WordPress WordPress 4.2
• WordPress WordPress 4.2.1
• WordPress WordPress 4.2.2
• WordPress WordPress 4.2.22
• WordPress WordPress 4.2.3
• WordPress WordPress 4.2.4
• WordPress WordPress 4.3
• WordPress WordPress 4.3.1
• WordPress WordPress 4.4.0
• WordPress WordPress 4.4.1
• WordPress WordPress 4.4.2
• WordPress WordPress 4.5.0
• WordPress WordPress 4.5.1
• WordPress WordPress 4.5.2
• WordPress WordPress 4.5.3
• WordPress WordPress 4.6
• WordPress WordPress 4.6.1
• WordPress WordPress 4.6.13
• WordPress WordPress 4.7
• WordPress WordPress 4.7.1
• WordPress WordPress 4.7.12
• WordPress WordPress 4.7.2
• WordPress WordPress 4.7.3
• WordPress WordPress 4.7.4
• WordPress WordPress 4.7.5
• WordPress WordPress 4.8.1
• WordPress WordPress 4.8.2
• WordPress WordPress 4.8.3
• WordPress WordPress 4.8.8
• WordPress WordPress 4.9
• WordPress WordPress 4.9.1
• WordPress WordPress 4.9.2
• WordPress WordPress 4.9.5
• WordPress WordPress 4.9.6
• WordPress WordPress 4.9.7
• WordPress WordPress 4.9.8
• WordPress WordPress 4.9.9
• WordPress WordPress 5.0
• WordPress WordPress 5.0.1
• WordPress WordPress 5.0.2
• WordPress WordPress 5.0.3
• WordPress WordPress 5.1.1
• WordPress WordPress 5.2
• WordPress WordPress 5.2.1
• WordPress WordPress 5.2.2
• WordPress WordPress 5.2.3
• WordPress WordPress 5.2.4
• WordPress WordPress 5.3

Recommendations

Block external access at the network boundary, unless external parties require service.
Filter access to the affected computer at the network boundary if global access isn’t needed. Restricting access to only trusted computers and networks might greatly reduce the likelihood of a successful exploit.

Run all software as a nonprivileged user with minimal access rights.
Attackers may successfully exploit client flaws in the browser through cross-site scripting vulnerabilities. When possible, run all software as a user with minimal privileges and limited access to system resources. Use additional precautions such as restrictive environments to insulate software that may potentially handle malicious content.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to detect and block attacks and anomalous activity such as requests containing suspicious URI sequences. Since the webserver may log such requests, review its logs regularly.

Do not follow links provided by unknown or untrusted sources.
Web users should be cautious about following links to sites that are provided by unfamiliar or suspicious sources. Filtering HTML from emails may help remove a possible vector for transmitting malicious links to users.

Set web browser security to disable the execution of script code or active content.
Since a successful exploit of these issues allows malicious code to execute in web clients, consider disabling support for script code and active content within the client browser. Note that this mitigation tactic might adversely affect legitimate websites that rely on the execution of browser-based script code.

Updates are available. Please see the references or vendor advisory for more information.