CVE intelligence and bounded remediation

CVE-2021-43863 — The Nextcloud Android app is the Android client for Nextcloud, a self-hosted productivity platform

High CVSS 7.5

The Nextcloud Android app is the Android client for Nextcloud, a self-hosted productivity platform. The Nextcloud Android app uses content providers to manage its data. Prior to version 3.18.1, the providers `FileContentProvider` and `DiskLruImageCacheFileProvider` have security issues (an SQL injection, and an insufficient permission control, respectively) that allow malicious apps in the same device to access Nextcloud's data bypassing the permission control system. Users should upgrade to version 3.18.1 to receive a patch. There are no known workarounds aside from upgrading.

Severity
High
CVSS
7.5 (3.1)
Published
2022-01-25
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-89

Affected products

  • nextcloud / nextcloud

Matched remediation archetype

SQL and data-query injection

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Check exposure

  • Trace request, message, file, and stored values into SQL, ORM query fragments, filters, sort expressions, and other data-query languages.
  • Inventory database roles, reachable schemas, multi-tenant boundaries, and whether stacked or administrative operations are enabled.
  • Check both direct queries and second-order use of previously stored values.

Remediate safely

  • Use parameterized queries or safe query builders for all values; map identifiers and operators through explicit allowlists.
  • Remove raw query concatenation and give the application account only the tables and operations it requires.
  • Update affected data-access components and add regression tests for query structure preservation with inert edge-case inputs.

Authoritative sources

Complete CVE record and remediation plan

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