# CVE-2021-27116: Privilege escalation in beego

> Local attackers can exploit symlink vulnerabilities in the profiling module to read or modify arbitrary files.

- **Severity:** High 7.8 (`CVSS:3.1/AC:L/AV:L/A:H/C:H/I:H/PR:L/S:U/UI:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Apr 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-ffjp-66mx-3qpj

## What is CVE-2021-27116?

CVE-2021-27116 is a high-severity path traversal vulnerability in n/a, published on 5 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in file profile.go in function MemProf in beego through 2.0.2, allows attackers to launch symlink attacks locally.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2021-27116?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/beego/beego` | Go | All versions | None |
| `github.com/beego/beego` | Go | All versions | None |
| `github.com/beego/beego/v2` | Go | From 2.0.0 | 2.0.2 |
| `github.com/beego/beego/v2` | Go | From 2.0.0 | 2.0.2 |

Products: Beego Beego.

## How do I fix CVE-2021-27116?

Upgrade to a fixed version.

## Is CVE-2021-27116 being exploited?

There is no known exploitation of CVE-2021-27116 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-2021-27116 and fix it if it is affected.

What it is: CVE-2021-27116 is a high-severity path traversal vulnerability in n/a, published on 5 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-27116 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/beego/beego (Go): affected all versions; no fix listed
- github.com/beego/beego (Go): affected all versions; no fix listed
- github.com/beego/beego/v2 (Go): affected from 2.0.0; fixed in 2.0.2
- github.com/beego/beego/v2 (Go): affected from 2.0.0; 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-2021-27116/ (Markdown: https://insights.sbomify.com/CVE-2021-27116/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27116
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27116
- OSV: https://osv.dev/vulnerability/CVE-2021-27116

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27116/
Summaries are generated and may contain mistakes; the official description above is the record.