Security readout for executives and security teams
Plain-English summary
This issue can let an unauthenticated remote attacker read server-side application classes and resources from certain Vaadin OSGi applications. The main business risk is confidentiality loss: exposed code or resources may reveal sensitive implementation details, secrets accidentally packaged with the app, or information useful for later attacks.
Executive priority
Prioritize remediation for internet-facing Vaadin OSGi applications and systems that may package sensitive resources. This is a high-severity confidentiality issue, not an availability or data-modification issue based on the supplied CVSS vector.
Technical view
CVE-2021-31407 is a CWE-402 exposure issue in Vaadin OSGi integration affecting com.vaadin:flow-server 1.2.0 through 2.4.7 and 6.0.0 through 6.0.1. A crafted HTTP request can access application classes and resources on the server. CVSS 3.1 is 8.6, with network access, low complexity, no privileges, and high confidentiality impact.
Likely exposure
Exposure is limited to applications using Vaadin OSGi integration in the affected Vaadin 12-14 and 19 / flow-server version ranges. Internet-facing Vaadin deployments have the highest practical exposure because the vulnerability is reachable over HTTP without authentication according to the CVSS vector.
Exploitation context
The provided sources support remote unauthenticated exploitability for information exposure, but do not show active exploitation. The CVE is not listed as KEV in the bundle. No public exploit status or exploitation telemetry is provided, so operational urgency should be based on exposure and sensitivity of server-side resources.
Researcher notes
The bundle identifies affected ranges and linked Vaadin issue and flow pull requests, but does not include detailed patch notes, exploit maturity, or indicators of compromise. Treat validation as dependency and deployment-scope confirmation, then follow Vaadin’s advisory for exact fixed-version guidance.
Mitigation direction
- Identify Vaadin OSGi applications using affected flow-server versions.
- Apply Vaadin vendor guidance and move to a fixed release outside affected ranges.
- Review packaged resources for secrets or sensitive internal files.
- Restrict external access where affected systems cannot be updated quickly.
- Monitor vendor advisory and related Vaadin issue and pull requests.
Validation and detection
- Inventory Vaadin and com.vaadin:flow-server versions in deployed applications.
- Confirm whether the application uses Vaadin OSGi integration.
- Map affected deployments to internet-facing and internal-only exposure.
- Review web logs for suspicious requests targeting server-side classes or resources.
- After updating, verify dependencies no longer match affected ranges.
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-402: 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-2021-31407 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
- 8.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
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:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://vaadin.com/security/cve-2021-31407CVE reference · x_refsource_MISC
- https://github.com/vaadin/osgi/issues/50CVE reference · x_refsource_MISC
- https://github.com/vaadin/flow/pull/10229CVE reference · x_refsource_MISC
- https://github.com/vaadin/flow/pull/10269CVE 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.
Transmission of Private Resources into a New Sphere ('Resource Leak')
Transmission of Private Resources into a New Sphere ('Resource Leak') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.