CVE-2020-27783

Public on

Last Modified: UTC

Description

A Cross-site Scripting (XSS) vulnerability was found in the python-lxml's clean module. The module's parser did not properly imitate browsers, causing different behaviors between the sanitizer and the user's page. This flaw allows a remote attacker to run arbitrary HTML/JS code. The highest threat from this vulnerability is to confidentiality and integrity.

A Cross-site Scripting (XSS) vulnerability was found in the python-lxml's clean module. The module's parser did not properly imitate browsers, causing different behaviors between the sanitizer and the user's page. This flaw allows a remote attacker to run arbitrary HTML/JS code. The highest threat from this vulnerability is to confidentiality and integrity.

Additional information

  • Bugzilla 1901633: python-lxml: mXSS due to the use of improper parser
  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • FAQ: Frequently asked questions about CVE-2020-27783

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

6.1

6.1

Attack Vector

Network

Network

Attack Complexity

Low

Low

Privileges Required

None

None

User Interaction

Required

Required

Scope

Changed

Changed

Confidentiality Impact

Low

Low

Integrity Impact

Low

Low

Availability Impact

None

None

CVSS v3 Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

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