CVE-2021-41178: nextcloud security-advisories Relative Path Traversal
Vulnerability summary
CVE-2021-41178 is a high (CVSS 8.8) Relative Path Traversal vulnerability in nextcloud security-advisories. EPSS estimates a 1.78% chance of exploitation in the next 30 days, higher than 77.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 25-10-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NDiffers
EPSS trend
Probability
1.78%
Chance of exploitation in the next 30 days
Percentile
78%
Versus all other CVEs
30-day change
0.00 pp
From 1.78% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-23Relative Path TraversalThe product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory.
- CWE-434Unrestricted Upload of File with Dangerous TypeThe product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
- CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Affected systems
Nextcloud2 products
- security-advisories20.0.13 | ≥ 21.0.0, < 21.0.5 | < 22.2.0
- server≥ 20.0.3, < 20.0.13 | ≥ 21.0.1, < 21.0.5 | ≥ 22.1.1, < 22.2.0
1 vendor · 2 products
References
4 links- github.com/nextcloud/security-advisories/security/advisories/GHSA-jp9c-vpr3-m5rfX Refsource CONFIRMThird Party Advisory