# CVE-2021-39391: Cross-site Scripting in Beego

> Attackers can inject malicious scripts via URI paths in the Beego admin panel, potentially compromising administrator sessions.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 Sep 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-c77f-4rgj-jfr4

## What is CVE-2021-39391?

CVE-2021-39391 is a medium-severity cross-site scripting vulnerability in n/a, published on 14 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Cross Site Scripting (XSS) vulnerability exists in the admin panel in Beego v2.0.1 via the URI path in an HTTP request, which is activated by administrators viewing the "Request Statistics" page.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-39391?

2 open source packages ship an affected version, including github.com/beego/beego/v2. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/beego/beego/v2` | Go | All versions | 2.0.2 |
| `github.com/beego/beego/v2` | Go | All versions | 2.0.2 |

Products: Beego Beego.

## How do I fix CVE-2021-39391?

Upgrade github.com/beego/beego/v2 to 2.0.2 or later.

## Is CVE-2021-39391 being exploited?

There is no known exploitation of CVE-2021-39391 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-31836](https://insights.sbomify.com/CVE-2022-31836/): Path Traversal in Beego (critical 9.8)
- [CVE-2022-31259](https://insights.sbomify.com/CVE-2022-31259/): Access control bypass in beego (critical 9.8)
- [CVE-2021-30080](https://insights.sbomify.com/CVE-2021-30080/): Access control bypass in Beego (critical 9.8)
- [CVE-2025-30223](https://insights.sbomify.com/CVE-2025-30223/): Beego allows Reflected/Stored XSS in Beego's RenderForm() Function Due to Unescaped User Input (critical 9.3)
- [CVE-2024-40464](https://insights.sbomify.com/CVE-2024-40464/): Beego privilege escalation vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-39391 and fix it if it is affected.

What it is: CVE-2021-39391 is a medium-severity cross-site scripting vulnerability in n/a, published on 14 Sep 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-39391 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/beego/beego/v2 (Go): affected all versions; fixed in 2.0.2
- github.com/beego/beego/v2 (Go): affected all versions; fixed in 2.0.2

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-2021-39391/ (Markdown: https://insights.sbomify.com/CVE-2021-39391/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-39391
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-39391
- OSV: https://osv.dev/vulnerability/CVE-2021-39391

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-39391/
Summaries are generated and may contain mistakes; the official description above is the record.