Path Traversal in Nextcloud Security-Advisories
CVE-2021-41178
Nextcloud is an open-source, self-hosted productivity platform. Prior to versions 20.0.13, 21.0.5, and 22.2.0, a file traversal vulnerability makes an attacker able to download arbitrary SVG images from the host system, including user provided files. This could also be leveraged into a XSS/phishing attack, an attacker could upload a malicious SVG file that mimics the Nextcloud login form and send a specially crafted link to victims. The XSS risk here is mitigated due to the fact that Nextcloud employs a strict Content-Security-Policy disallowing execution of arbitrary JavaScript. It is recommended that the Nextcloud Server be upgraded to 20.0.13, 21.0.5 or 22.2.0. There are no known workarounds aside from upgrading.
EPSS: 0.018 (76.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Nextcloud Security-advisories — versions 20.0.13, >= 21.0.0, < 21.0.5, < 22.2.0
- Nextcloud Server
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Permissions Required, x_refsource_MISC)
- security-advisories@github.com (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
Frequently asked questions
- What is CVE-2021-41178?
- CVE-2021-41178 is a high-severity vulnerability in Nextcloud Security-Advisories, classified under Relative Path Traversal. CVSS score: 8.8/10. Published 2021-10-25.
- How severe is CVE-2021-41178?
- High severity. CVSS v3 base score is 8.8 out of 10.