CVE-2021-39220

Bypass of image blocking in Nextcloud Mail

Description

Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. It is recommended that the Nextcloud Mail application is upgraded to 1.10.4 or 1.11.0. There are no known workarounds aside from upgrading.

Category

3.5
CVSS
Severity: Low
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.26%
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-6q9v-wm8r-rcv5 third party advisory
https://github.com/nextcloud/mail/pull/5470 third party advisory patch
https://hackerone.com/reports/1308147 permissions required

Frequently Asked Questions

What is the severity of CVE-2021-39220?
CVE-2021-39220 has been scored as a low severity vulnerability.
How to fix CVE-2021-39220?
To fix CVE-2021-39220, 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-2021-39220 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-39220 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-2021-39220?
CVE-2021-39220 affects nextcloud security-advisories.
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