XSS in Nextcloud Desktop

CVE-2020-8189

A cross-site scripting error in Nextcloud Desktop client 2.6.4 allowed to present any html (including local links) when responding with invalid data on the login attempt.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.014 (69.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-8189?
CVE-2020-8189 is a medium-severity vulnerability in Nextcloud Desktop, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2020-08-21.
How severe is CVE-2020-8189?
Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2020-8189 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.