Bug 2018286 (CVE-2021-41178)

Summary: CVE-2021-41178 nextcloud: file traversal affecting SVG files
Product: [Other] Security Response Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED UPSTREAM QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: ce, james.hogarth
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Last Closed: 2021-10-28 20:07:54 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2018287    
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Description Guilherme de Almeida Suckevicz 2021-10-28 17:55:03 UTC 
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.

Reference:
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-jp9c-vpr3-m5rf
Comment 1 Guilherme de Almeida Suckevicz 2021-10-28 17:55:15 UTC 
Created nextcloud tracking bugs for this issue:

Affects: fedora-all [bug 2018287]
Comment 2 Product Security DevOps Team 2021-10-28 20:07:54 UTC 
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.