Security readout for executives and security teams
Plain-English summary
The Nextcloud Android app could leave sensitive data behind when a user removed an account. The disclosed examples include End-to-End encryption keys. Business risk is mainly tied to shared, lost, reassigned, or compromised Android devices where old app data remains accessible.
Executive priority
Handle as a targeted mobile data hygiene issue, not a broad remote compromise. Prioritize updating managed Android fleets and reviewing higher-risk device lifecycle cases involving account removal and encryption keys.
Technical view
CVE-2021-32658 is a CWE-200 information exposure in Nextcloud Android versions before 3.16.1. A timeout issue could prevent complete cleanup of sensitive local data during account removal. CVSS 3.1 is 4.7, with local access, low privileges, high attack complexity, and high confidentiality impact.
Likely exposure
Exposure is likely limited to Android devices running Nextcloud Android before 3.16.1, especially where accounts were removed while End-to-End encryption was used or devices were shared, returned, or reassigned.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. The CVSS vector indicates local access and low privileges are required, with high complexity and no user interaction after access.
Researcher notes
Evidence identifies a timeout-related cleanup failure on account removal, with possible retention of sensitive key material. Public sources name the fixed version as 3.16.1. The bundle does not provide proof of exploitation or detailed affected platform conditions beyond Android client versions before 3.16.1.
Mitigation direction
- Upgrade Nextcloud Android App to version 3.16.1 or newer.
- Prioritize managed, shared, lost, returned, or reassigned Android devices.
- Review vendor guidance for cleanup of previously removed accounts.
- Treat exposed End-to-End encryption keys as sensitive if old device data may remain.
Validation and detection
- Inventory Android devices for Nextcloud Android versions below 3.16.1.
- Confirm managed app stores or MDM enforce 3.16.1 or newer.
- Identify users who removed accounts on vulnerable app versions.
- Check whether affected users enabled End-to-End encryption.
- Review device return and reassignment processes for app data cleanup.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-32658 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N13.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.7MediumVector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g5gf-rmhm-wpxwCVE reference · x_refsource_CONFIRM
- https://github.com/nextcloud/android/commit/355f3c745b464b741b20a3b96597303490c26333CVE reference · x_refsource_MISC
- https://hackerone.com/reports/1189168CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.