XSS in Collabora Online
CVE-2021-43817
Collabora Online is a collaborative online office suite based on LibreOffice technology. In affected versions a reflected XSS vulnerability was found in Collabora Online. An attacker could inject unescaped HTML into a variable as they created the Collabora Online iframe, and execute scripts inside the context of the Collabora Online iframe. This would give access to a small set of user settings stored in the browser, as well as the session's authentication token which was also passed in at iframe creation time. Users should upgrade to Collabora Online 6.4.16 or higher or Collabora Online 4.2.20 or higher. Collabora Online Development Edition 21.11 is not affected.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.006 (48.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N.
Affected products
- Collabora Online
- Collaboraonline Online — versions >= 6.0.0, < 6.4.16, < 4.2.20
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-43817?
- CVE-2021-43817 is a high-severity vulnerability in Collabora Online, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2021-12-13.
- How severe is CVE-2021-43817?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2021-43817 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.