Security readout for executives and security teams
Plain-English summary
Samsung Notes before version 4.2.04.27 had an access-control flaw that could let an untrusted app access local files. The main business concern is unintended exposure of notes or device-local data where Samsung Notes is installed and not updated.
Executive priority
Treat this as a mobile data-exposure issue. It is not marked as actively exploited in the provided sources, but devices running outdated Samsung Notes should be updated through normal mobile patch governance.
Technical view
CVE-2021-25405 is a CWE-284 improper access control issue in ScreenOffActivity in Samsung Notes. The public record states that versions prior to 4.2.04.27 allow untrusted applications to access local files. No CVSS vector, detailed prerequisites, or affected platform matrix is provided.
Likely exposure
Exposure is likely limited to Android devices with Samsung Notes installed below version 4.2.04.27. Risk is higher where employees store sensitive business, customer, or credential-adjacent information in local notes.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Public information only states that untrusted applications can access local files; it does not describe exploit maturity, required permissions, or user interaction.
Researcher notes
Public details are sparse. The key technical facts are ScreenOffActivity, improper access control, Samsung Notes before 4.2.04.27, and local file access by untrusted applications. Avoid assuming scope beyond Samsung Notes without vendor confirmation.
Mitigation direction
- Update Samsung Notes to version 4.2.04.27 or later.
- Review Samsung Mobile's May 2021 advisory for vendor guidance.
- Inventory managed devices for outdated Samsung Notes installations.
- Restrict sensitive business use of Samsung Notes until devices are updated.
- Remove untrusted apps from affected devices under mobile security policy.
Validation and detection
- Confirm Samsung Notes version is 4.2.04.27 or later on managed devices.
- Check MDM or endpoint inventory for older Samsung Notes versions.
- Verify mobile app update policies cover Samsung Notes.
- Review device app lists for untrusted or unmanaged applications.
- Document any devices that cannot be updated and their compensating controls.
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-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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-2021-25405 mapping review
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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://security.samsungmobile.com/serviceWeb.smsb?year=2021&month=5CVE 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 Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.