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CVE-2021-39221

MEDIUMCVSS 5.4/10EPSS 0.50%

Last modified

CVE-2021-39221 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Contacts application prior to version 4.0.3 was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. EPSS estimates a 0.50% chance of exploitation in the next 30 days.

Description

Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Contacts application prior to version 4.0.3 was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation, a user would need to right-click on a malicious file and open the file in a new tab. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Contacts application is upgraded to 4.0.3. As a workaround, one may use a browser that has support for Content-Security-Policy.

Metrics

CVSS 3.1
5.4/10

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

EPSS Probability
0.50%

39.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
NextcloudContacts< 4.0.3

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-39221?
Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Contacts application prior to version 4.0.3 was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation, a user would need to right-click on a malicious file and open the file in a new tab. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Contacts application is upgraded to 4.0.3. As a workaround, one may use a browser that has support for Content-Security-Policy.
How severe is CVE-2021-39221?
CVE-2021-39221 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.50% probability of exploitation in the next 30 days.
How do I fix CVE-2021-39221?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-39221?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST