# CVE-2021-4274: sileht bird-lg layout.html cross site scripting

> Remote attackers can execute arbitrary scripts via the request_args parameter in bird-lg, potentially compromising user sessions.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 21 Dec 2022
- **Updated:** 14 Apr 2025
- **Also known as:** GHSA-xjrp-9qff-8prg

## What is CVE-2021-4274?

CVE-2021-4274 is a low-severity cross-site scripting vulnerability in sileht bird-lg, published on 21 Dec 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A vulnerability, which was classified as problematic, has been found in sileht bird-lg. This issue affects some unknown processing of the file templates/layout.html. The manipulation of the argument request_args leads to cross site scripting. The attack may be initiated remotely. The name of the patch is ef6b32c527478fefe7a4436e10b96ee28ed5b308. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-216479.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-707 (Improper Neutralization)

## Which versions are affected by CVE-2021-4274?

It affects 1 product.


Products: Bird-Lg Project Bird-Lg.

## How do I fix CVE-2021-4274?

No fix has been published for CVE-2021-4274 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4274 being exploited?

There is no known exploitation of CVE-2021-4274 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4274 and fix it if it is affected.

What it is: CVE-2021-4274 is a low-severity cross-site scripting vulnerability in sileht bird-lg, published on 21 Dec 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-4274 in the wild and no public exploit code.

Affected product: sileht bird-lg. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2021-4274/ (Markdown: https://insights.sbomify.com/CVE-2021-4274/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4274
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4274
- OSV: https://osv.dev/vulnerability/CVE-2021-4274

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-4274/
Summaries are generated and may contain mistakes; the official description above is the record.