In Mozilla Bleach before 3.11, a mutation XSS affects users calling bleach.clean with noscript and a raw tag in the allowed/whitelisted tags option.

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8077-1 advisory.

    It was discovered that Bleach did not properly sanitize URI attributes containing character entities. An     attacker could possibly use this issue to construct a URI with a disallowed scheme that would bypass     sanitization, leading to cross-site scripting. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-7753)

    Yaniv Nizry discovered that Bleach was vulnerable to a mutation cross-site scripting issue when sanitizing     HTML with the noscript tag and a raw tag in the allowed tags list. An attacker could possibly use this     issue to inject malicious content, leading to cross-site scripting. This issue only affected Ubuntu 18.04     LTS. (CVE-2020-6802)

    Yaniv Nizry discovered that Bleach was vulnerable to a mutation cross-site scripting issue when sanitizing     HTML with RCDATA together with svg or math tags in the allowed tags list. An attacker could possibly use     this issue to inject malicious content, leading to cross-site scripting. (CVE-2020-6816)

    It was discovered that Bleach incorrectly handled parsing of style attributes when sanitizing HTML. An     attacker could possibly use this issue to perform a regular expression denial of service, leading to     excessive resource consumption. (CVE-2020-6817)

    Yaniv Nizry and Micha Bentkowski discovered that Bleach was vulnerable to a mutation cross-site     scripting issue when sanitizing HTML with certain combinations of allowed tags. An attacker could possibly     use this issue to inject malicious content, leading to cross-site scripting. (CVE-2021-23980)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Update to version 3.1.4, an upstream security release. See the [upstream changelog](https://github.com/mozilla/bleach/blob/v3.1.4/CHANGES) for details.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for python-bleach to version 3.1.1 fixes the following issue :

  - Python-bleach was updated to 3.1.1

  - CVE-2020-6802: Fixed mutation XSS vulnerabilities     (boo#1165303).

It was reported that python-bleach, a whitelist-based HTML-sanitizing library, is prone to a mutation XSS vulnerability in bleach.clean when'noscript' and one or more raw text tags were whitelisted.

ID	Name	Product	Family	Severity
301534	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : Bleach vulnerabilities (USN-8077-1)	Nessus	Ubuntu Local Security Checks	critical
136156	Fedora 31 : python-bleach (2020-e1fa96c506)	Nessus	Fedora Local Security Checks	medium
136153	Fedora 30 : python-bleach (2020-827b677e15)	Nessus	Fedora Local Security Checks	medium
134347	openSUSE Security Update : python-bleach (openSUSE-2020-308)	Nessus	SuSE Local Security Checks	medium
134183	Debian DSA-4636-1 : python-bleach - security update	Nessus	Debian Local Security Checks	medium

Detections

Analytics

CVE-2020-6802

medium

Tenable Plugins

critical

medium

medium

medium

medium