Security readout for executives and security teams
Plain-English summary
CVE-2021-38688 is an improper authentication flaw in QNAP's Android Qfile app. A successful attack could compromise the app and expose information. QNAP states the issue is fixed in Qfile 3.0.0.1105 and later.
Executive priority
Treat as a high-priority mobile app update for users who access QNAP files through Android Qfile. The main business concern is unauthorized app compromise and information exposure, not confirmed widespread exploitation.
Technical view
The CVE is classified as CWE-287 improper authentication affecting QNAP Qfile for Android. CVSS 3.1 is 7.1 high, with adjacent attack vector, high complexity, no privileges required, user interaction required, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely on Android devices running QNAP Qfile versions earlier than 3.0.0.1105. The CVE record does not specify exact vulnerable version ranges beyond the fixed version threshold.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. CVSS indicates exploitation is constrained by adjacent access, high complexity, and user interaction, but impact is high if successful.
Researcher notes
Public details are limited. The bundle names improper authentication, Qfile for Android, CVSS vector, and fixed version, but does not provide affected version ranges, exploit mechanics, indicators, or workaround details.
Mitigation direction
- Update Qfile for Android to version 3.0.0.1105 or later.
- Inventory managed Android devices for installed Qfile versions.
- Use MDM or app-store controls to enforce the fixed version.
- Check QNAP advisory QSA-21-55 for current vendor guidance.
Validation and detection
- Confirm Qfile version is 3.0.0.1105 or later on each device.
- Review mobile asset inventory for unmanaged or outdated Qfile installations.
- Verify app updates came from trusted vendor or official app sources.
- Document exceptions where vulnerable versions cannot be upgraded.
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-287: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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-2021-38688 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
- High
- CVSS
- 7.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
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:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H1.25.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.1HighVector: CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.qnap.com/en/security-advisory/qsa-21-55CVE 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 Authentication
Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.