Security readout for executives and security teams
Plain-English summary
CVE-2021-31409 is a denial-of-service risk in Vaadin’s email validation component. A remote unauthenticated attacker could submit specially crafted email input that consumes excessive server resources, potentially degrading or taking down affected applications.
Executive priority
Treat this as a high-priority availability issue for internet-facing Vaadin applications, especially customer-facing portals or revenue-critical forms.
Technical view
The source bundle describes unsafe regular expression validation in com.vaadin:vaadin-compatibility-server, Vaadin 8.0.0 through 8.12.4. The CVSS 3.1 vector is network-accessible, low complexity, no privileges, no user interaction, with availability impact only.
Likely exposure
Exposure is most likely in Vaadin applications using affected Vaadin 8 or vaadin-compatibility-server versions where EmailValidator processes untrusted email input.
Exploitation context
The bundle does not report known active exploitation, and KEV is false. Exploitability is still meaningful because the CVSS vector indicates remote, unauthenticated availability impact.
Researcher notes
The provided bundle has a title/description mismatch: the title mentions Vaadin 18-19 logout behavior, while the description and CWE describe Vaadin 8 EmailValidator resource consumption. Analysis follows the description, CVSS, CWE, and listed references.
Mitigation direction
- Check Vaadin’s advisory for the supported fixed version and upgrade guidance.
- Inventory applications using Vaadin 8.0.0 through 8.12.4.
- Prioritize exposed forms that validate attacker-controlled email addresses.
- Avoid exposing affected validation paths until vendor-guided remediation is complete.
Validation and detection
- Review dependency manifests for com.vaadin:vaadin-compatibility-server versions 8.0.0 through 8.12.4.
- Identify public routes or APIs accepting email input into Vaadin EmailValidator.
- Confirm remediation by verifying dependency versions after upgrade.
- Review logs and monitoring for unexplained resource spikes on email-validation endpoints.
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-400: 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-2021-31409 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://vaadin.com/security/cve-2021-31409CVE reference · x_refsource_CONFIRM
- https://github.com/vaadin/framework/issues/12240CVE reference · x_refsource_CONFIRM
- https://github.com/vaadin/framework/pull/12241CVE reference · x_refsource_CONFIRM
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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.