# CVE-2021-31649: JFinal Java Deserialization Vulnerability

> Attackers can achieve remote code execution in applications using the jfinal framework with Redis if unsafe deserialization is enabled.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-h3j8-fr5q-8rfr

## What is CVE-2021-31649?

CVE-2021-31649 is a critical unsafe deserialization vulnerability in n/a, published on 24 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In applications using jfinal 4.9.08 and below, there is a deserialization vulnerability when using redis,may be vulnerable to remote code execute

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2021-31649?

2 open source packages ship an affected version, including com.jfinal:jfinal. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.jfinal:jfinal` | Maven | All versions to 4.9.08 | None |
| `com.jfinal:jfinal` | Maven | All versions to 4.9.08 | None |

Products: Jfinal Jfinal.

## How do I fix CVE-2021-31649?

No fix has been published for CVE-2021-31649 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-31649 being exploited?

There is no known exploitation of CVE-2021-31649 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-31635](https://insights.sbomify.com/CVE-2021-31635/): jFinal Server-Side Template Injection vulnerability (critical 9.8)
- [CVE-2019-17352](https://insights.sbomify.com/CVE-2019-17352/): JFinal file validation vulnerability (high 7.5)
- [CVE-2021-33348](https://insights.sbomify.com/CVE-2021-33348/): Cross-site scripting in jfinal (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31649 and fix it if it is affected.

What it is: CVE-2021-31649 is a critical unsafe deserialization vulnerability in n/a, published on 24 Jun 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-2021-31649 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.jfinal:jfinal (Maven): affected all versions up to 4.9.08; no fix listed
- com.jfinal:jfinal (Maven): affected all versions up to 4.9.08; no fix listed

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-2021-31649/ (Markdown: https://insights.sbomify.com/CVE-2021-31649/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31649
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31649
- OSV: https://osv.dev/vulnerability/CVE-2021-31649

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31649/
Summaries are generated and may contain mistakes; the official description above is the record.