CVE-2021-32733

XSS in Nextcloud Text application

Description

Nextcloud Text is a collaborative document editing application that uses Markdown. A cross-site scripting vulnerability is present in versions prior to 19.0.13, 20.0.11, and 21.0.3. The Nextcloud Text application shipped with Nextcloud server used a `text/html` Content-Type when serving files to users. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. As a workaround, use a browser that has support for Content-Security-Policy.

Category

4.8
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.17%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: nextcloud security-advisories
Published at:
Updated at:

References

Link Tags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-x4w3-jhcr-57pq third party advisory
https://github.com/nextcloud/text/pull/1689 third party advisory patch
https://hackerone.com/reports/1241460 permissions required

Frequently Asked Questions

What is the severity of CVE-2021-32733?
CVE-2021-32733 has been scored as a medium severity vulnerability.
How to fix CVE-2021-32733?
To fix CVE-2021-32733, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-32733 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-32733 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-32733?
CVE-2021-32733 affects nextcloud security-advisories.
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