# CVE-2020-1340: Cross-site scripting in NuGetGallery

> Attackers can inject malicious scripts into NuGet package metadata, potentially compromising user sessions or executing code in the NuGetGallery web interface.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/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:** 9 Jun 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-jfw3-6x4x-gprc

## What is CVE-2020-1340?

CVE-2020-1340 is a medium-severity cross-site scripting vulnerability in Microsoft NuGetGallery, published on 9 Jun 2020. 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 spoofing vulnerability exists when the NuGetGallery does not properly sanitize input on package metadata values, aka 'NuGetGallery Spoofing Vulnerability'.

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

## Which versions are affected by CVE-2020-1340?

It affects 1 product.


Products: Microsoft Nugetgallery.

## How do I fix CVE-2020-1340?

No fix has been published for CVE-2020-1340 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1340 being exploited?

There is no known exploitation of CVE-2020-1340 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft NuGetGallery

- [CVE-2024-47604](https://insights.sbomify.com/CVE-2024-47604/): XSS vulnerability in NuGetGallery HTML attributes handling (high 8.2)
- [CVE-2024-54138](https://insights.sbomify.com/CVE-2024-54138/): XSS Vulnerability in NuGetGallery's Markdown Autolinks Processing (medium 6.9)
- [CVE-2024-37304](https://insights.sbomify.com/CVE-2024-37304/): NuGetGallery's Markdown Autolinks Processing Vulnerable to Cross-site Scripting (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-1340 and fix it if it is affected.

What it is: CVE-2020-1340 is a medium-severity cross-site scripting vulnerability in Microsoft NuGetGallery, published on 9 Jun 2020. 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-2020-1340 in the wild and no public exploit code.

Affected product: Microsoft NuGetGallery. 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-2020-1340/ (Markdown: https://insights.sbomify.com/CVE-2020-1340/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1340
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1340
- OSV: https://osv.dev/vulnerability/CVE-2020-1340

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1340/
Summaries are generated and may contain mistakes; the official description above is the record.