Security readout for executives and security teams
Plain-English summary
CVE-2019-5455 is a lock-bypass issue in the Nextcloud Android app related to aborting multi-account creation. If triggered, the app’s lock protection may not prevent access as intended. Public data does not show active exploitation, a CVSS score, or detailed remediation text.
Executive priority
Treat as a mobile data-protection issue, not a broad network compromise. Prioritize if staff use Nextcloud Android for sensitive files, especially on BYOD or lightly managed devices.
Technical view
The CVE describes CWE-288 authentication bypass affecting Nextcloud Android client lock protection. The description names app version 3.6.0, while the supplied affected metadata lists com.nextcloud.client 3.6.1, creating version ambiguity. The public reference is a HackerOne report; no KEV listing is present.
Likely exposure
Exposure is most relevant to Android devices using the Nextcloud client with app lock enabled. Risk is higher where devices store sensitive synced files or are shared, lost, or managed under weak mobile controls.
Exploitation context
The issue appears to require interaction with the mobile app’s multi-account setup flow and access to the device or app session. Sources do not indicate remote exploitation or exploitation in the wild.
Researcher notes
Public metadata is sparse and internally inconsistent on affected versioning. Avoid assuming a fixed version from the CVE alone. Use the HackerOne report and Nextcloud release notes to resolve version scope before closure.
Mitigation direction
- Check Nextcloud’s advisory or release history for the corrected Android client version.
- Update the Nextcloud Android app through trusted app stores or managed deployment.
- Use MDM to block outdated Nextcloud Android client versions where possible.
- Require strong device-level screen lock and encryption on managed Android devices.
Validation and detection
- Inventory Android devices running the Nextcloud client and record exact app versions.
- Review whether app lock is enabled for users handling sensitive data.
- Confirm deployed versions are not those identified by vendor guidance as affected.
- Monitor vendor and HackerOne references for clarification on affected and fixed versions.
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-2019-5455 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/490946CVE 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.