# CVE-2021-29047: Liferay Portal and Liferay DXP Fails to Invalidate CAPTCHA Answers After Use

> Attackers can bypass CAPTCHA protection in Liferay Portal by reusing valid answers, allowing repeated execution of protected actions.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 May 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-9mxg-p873-6793

## What is CVE-2021-29047?

CVE-2021-29047 is a high-severity vulnerability in Liferay Liferay Portal, published on 16 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2021-29047?

4 open source packages ship an affected version, including com.liferay.portal:release.dxp.bom and com.liferay.portal:release.portal.bom. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.liferay.portal:release.dxp.bom` | Maven | All versions | 7.3.10.fp1 |
| `com.liferay.portal:release.dxp.bom` | Maven | All versions | 7.3.10.fp1 |
| `com.liferay.portal:release.portal.bom` | Maven | From 7.3.4 | 7.3.6 |
| `com.liferay.portal:release.portal.bom` | Maven | From 7.3.4 | 7.3.6 |

Products: Liferay Dxp, Liferay Liferay Portal.

## How do I fix CVE-2021-29047?

Upgrade com.liferay.portal:release.dxp.bom to 7.3.10.fp1 or later.

## Is CVE-2021-29047 being exploited?

There is no known exploitation of CVE-2021-29047 in the wild and no public exploit code.

## Other vulnerabilities in Liferay Liferay Portal

- [CVE-2022-42120](https://insights.sbomify.com/CVE-2022-42120/): Liferay Portal and Liferay DXP Vulnerable to SQL Injection via the Fragment Module (critical 9.8)
- [CVE-2022-42122](https://insights.sbomify.com/CVE-2022-42122/): Liferay Portal and Liferay DXP Vulnerable to SQL Injection via Friendly URL Module (critical 9.8)
- [CVE-2023-35030](https://insights.sbomify.com/CVE-2023-35030/): Liferay Portal and Liferay DXP Vulnerable to CSRF via the Layout Module (high 8.8)
- [CVE-2021-29053](https://insights.sbomify.com/CVE-2021-29053/): Liferay Portal and Liferay DXP Vulnerable to Multiple SQL Injections (high 8.8)
- [CVE-2021-33321](https://insights.sbomify.com/CVE-2021-33321/): Liferay Portal and Liferay DXP insecure default configuration (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-29047 and fix it if it is affected.

What it is: CVE-2021-29047 is a high-severity vulnerability in Liferay Liferay Portal, published on 16 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-29047 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.liferay.portal:release.dxp.bom (Maven): affected all versions; fixed in 7.3.10.fp1
- com.liferay.portal:release.dxp.bom (Maven): affected all versions; fixed in 7.3.10.fp1
- com.liferay.portal:release.portal.bom (Maven): affected from 7.3.4; fixed in 7.3.6
- com.liferay.portal:release.portal.bom (Maven): affected from 7.3.4; fixed in 7.3.6

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-29047/ (Markdown: https://insights.sbomify.com/CVE-2021-29047/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-29047
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-29047
- OSV: https://osv.dev/vulnerability/CVE-2021-29047

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-29047/
Summaries are generated and may contain mistakes; the official description above is the record.