Security readout for executives and security teams
Plain-English summary
CVE-2019-5453 is a lock-protection bypass in the Nextcloud Android app before version 3.3.0. If the app prompts for its lock, switching to the Nextcloud file provider could still allow file access. The main business concern is unauthorized access to synced corporate files on affected Android devices.
Executive priority
Treat this as a mobile data-access control issue. Prioritize remediation where Android devices store sensitive Nextcloud files or where users rely on the app lock for protection. It is not presented as a server-side compromise or actively exploited issue in the provided sources.
Technical view
The issue is classified as CWE-288, authentication bypass using an alternate path or channel. Public CVE data describes bypassing the app lock by moving from the lock prompt to the Nextcloud file provider. The public record does not provide CVSS scoring or detailed environmental prerequisites.
Likely exposure
Exposure is limited to Android devices running the Nextcloud client prior to 3.3.0, especially where the app lock feature is used to protect local file access. Organizations without managed mobile inventory may have difficulty confirming affected versions.
Exploitation context
The source bundle does not indicate active exploitation, and CISA KEV status is false. The scenario appears to require access to the affected Android app/device context rather than remote server compromise. Public details are limited to the vulnerability description and HackerOne reference.
Researcher notes
The public data is sparse: no CVSS vector, no detailed affected-version range beyond “prior to 3.3.0,” and no KEV listing. The core weakness is an alternate-channel bypass of local app lock protection through the file provider interface.
Mitigation direction
- Identify Android devices using the Nextcloud app.
- Upgrade affected clients to version 3.3.0 or later.
- Check Nextcloud vendor guidance for any additional mobile security recommendations.
- Use MDM controls to enforce minimum app versions where available.
- Review mobile device lock and lost-device procedures.
Validation and detection
- Confirm installed Nextcloud Android app versions across managed devices.
- Flag any version earlier than 3.3.0 for remediation.
- Verify app-store or MDM deployment status after updates.
- Review whether sensitive files are synced to affected Android devices.
- Check vendor advisory or HackerOne report for any updated guidance.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-288: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2019-5453 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://hackerone.com/reports/331489CVE 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.
Authentication Bypass Using an Alternate Path or Channel
Authentication Bypass Using an Alternate Path or Channel represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.