Security readout for executives and security teams
Plain-English summary
CVE-2019-5450 is a low-impact UI sanitization issue in the Nextcloud Android app before version 3.7.0. A folder name containing basic HTML could change how the directory name appears in the app’s header bar. Public sources do not indicate data theft, code execution, or active exploitation.
Executive priority
Treat as routine patching, not an emergency. The known impact is visual manipulation inside the Android app, but outdated mobile clients should still be updated to reduce avoidable trust and UI integrity risks.
Technical view
The vulnerability is CWE-80 improper neutralization of HTML in directory names. In Nextcloud Android app versions prior to 3.7.0, basic HTML in a directory name was not properly sanitized before display in the header bar, allowing visual styling of that UI element.
Likely exposure
Exposure is limited to users of the Nextcloud Android app prior to 3.7.0 who encounter directory names containing basic HTML. Risk is higher where users accept or sync folders with names controlled by other users.
Exploitation context
The provided sources describe UI styling via unsanitized HTML in directory names. They do not report active exploitation, weaponized public exploit activity, authentication impact, or remote code execution. The CVE is not listed as CISA KEV in the provided bundle.
Researcher notes
The public record lacks CVSS scoring and detailed exploit conditions. Analysis should stay constrained to the documented behavior: basic HTML styling of directory names in the header bar on pre-3.7.0 Android clients.
Mitigation direction
- Update the Nextcloud Android app to version 3.7.0 or later.
- Prioritize managed mobile devices still running pre-3.7.0 versions.
- Limit interaction with untrusted shared folders until affected clients are updated.
- Review Nextcloud and HackerOne references for any additional vendor guidance.
Validation and detection
- Inventory Android devices using the Nextcloud client.
- Confirm installed Nextcloud Android app versions are 3.7.0 or later.
- Review mobile app management records for outdated installations.
- Check whether users receive folders or shares from untrusted parties.
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-80: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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-2019-5450 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/631227CVE 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.
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.