How severe is CVE-2021-43863?

CVE-2021-43863 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-43863 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43863?

CVE-2021-43863 affects Nextcloud. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43863?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-43863 published?

CVE-2021-43863 was published on 2022-01-25 and last updated on 2026-06-17.

CVE-2021-43863

CVE-2021-43863 is a high-severity vulnerability in Nextcloud with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-89.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-89
Affected product: Nextcloud
Published: 2022-01-25
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-43863?: 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.
How severe is CVE-2021-43863?: CVE-2021-43863 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-43863 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43863?: CVE-2021-43863 affects Nextcloud. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43863?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-43863 published?: CVE-2021-43863 was published on 2022-01-25 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:nextcloud:*:*:*:*:*:android:*:*

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