SB2021060711 - Multiple vulnerabilities in TinyMCE

Description

This security bulletin contains information about 2 vulnerabilities.

1) Cross-site scripting (CVE-ID: N/A)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

2) Cross-site scripting (CVE-ID: N/A)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to execute arbitrary JavaScript.

The vulnerability exists due to improper neutralization of input during web page generation in the core parser for form elements when processing specially crafted content inserted through the clipboard or APIs and later rendering or previewing the content outside of the editor. A remote attacker can insert specially crafted content to execute arbitrary JavaScript.

The issue can only be triggered when the content is previewed or rendered outside of the editor, because forms cannot be submitted while editing.

Remediation

Install update from vendor's website.

References

• https://github.com/tinymce/tinymce/commit/09bfb1dcb176611d22a477666d8cea72cd14c3fe
• https://www.tiny.cloud/docs/release-notes/release-notes571/#securityfixes
• https://github.com/tinymce/tinymce/security/advisories/GHSA-5vm8-hhgr-jcjp