CVE-2021-32671

Published on: 06/07/2021 12:00:00 AM UTC

Last Modified on: 06/17/2021 03:37:00 PM UTC

CVE-2021-32671 - advisory for GHSA-5qjq-69w6-fg57

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

Certain versions of Flarum from Flarum contain the following vulnerability:

Flarum is a forum software for building communities. Flarum's translation system allowed for string inputs to be converted into HTML DOM nodes when rendered. This change was made after v0.1.0-beta.16 (our last beta before v1.0.0) and was not noticed or documented. This allowed for any user to type malicious HTML markup within certain user input fields and have this execute on client browsers. The example which led to the discovery of this vulnerability was in the forum search box. Entering faux-malicious HTML markup, such as <script>alert('test')</script> resulted in an alert box appearing on the forum. This attack could also be modified to perform AJAX requests on behalf of a user, possibly deleting discussions, modifying their settings or profile, or even modifying settings on the Admin panel if the attack was targetted towards a privileged user. All Flarum communities that run flarum v1.0.0 or v1.0.1 are impacted. The vulnerability has been fixed and published as flarum/core v1.0.2. All communities running Flarum v1.0 have to upgrade as soon as possible to v1.0.2.

CVE-2021-32671 has been assigned by [email protected] to track the vulnerability - currently rated as CRITICAL severity.
Affected Vendor/Software: flarum - core version >= 1.0.0, < 1.0.2

CVSS3 Score: 10 - CRITICAL

Attack Vector ^ⓘ	Attack Complexity	Privileges Required	User Interaction
NETWORK	LOW	NONE	NONE
Scope	Confidentiality Impact	Integrity Impact	Availability Impact
CHANGED	HIGH	HIGH	HIGH

CVSS2 Score: 4.3 - MEDIUM

Access Vector^ⓘ	Access Complexity	Authentication
NETWORK	MEDIUM	NONE
Confidentiality Impact	Integrity Impact	Availability Impact
NONE	PARTIAL	NONE

CVE References

Description	Tags ^ⓘ	Link
XSS vulnerability with translator · Advisory · flarum/core · GitHub	github.com text/html	CONFIRM github.com/flarum/core/security/advisories/GHSA-5qjq-69w6-fg57
Fix XSS vulnerability · flarum/[email protected] · GitHub	github.com text/html	MISC github.com/flarum/core/commit/440bed81b8019dff00642c8f493b4909d505a28a
flarum/core - Packagist	packagist.org text/html	MISC packagist.org/packages/flarum/core

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There are currently no QIDs associated with this CVE

Known Affected Configurations (CPE V2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Application	Flarum	Flarum	1.0.0	All	All	All
Application	Flarum	Flarum	1.0.1	All	All	All

cpe:2.3:a:flarum:flarum:1.0.0:*:*:*:*:*:*:*:
cpe:2.3:a:flarum:flarum:1.0.1:*:*:*:*:*:*:*:

No vendor comments have been submitted for this CVE

Social Mentions

Source	Title	Posted (UTC)
@CVEreport	CVE-2021-32671 : Flarum is a forum software for building communities. Flarum's translation system allowed for strin… twitter.com/i/web/status/1…	2021-06-07 21:31:23
/r/netcve	CVE-2021-32671	2021-06-07 21:41:59