# CVE-2020-1112: Windows Background Intelligent Transfer Service Elevation of Privilege Vulnerability

> An attacker with upload permissions can exploit improper file validation in Windows BITS to upload restricted files, leading to privilege escalation.

- **Severity:** High 8.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 May 2020
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-2p7m-73cj-2m99

## What is CVE-2020-1112?

CVE-2020-1112 is a high-severity vulnerability in Microsoft Windows 10, published on 21 May 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An elevation of privilege vulnerability exists when the Windows Background Intelligent Transfer Service (BITS) IIS module improperly handles uploaded content. An attacker who successfully exploited this vulnerability could upload restricted file types to an IIS-hosted folder.
To exploit this vulnerability, an attacker would require permissions to upload files via BITS. An attacker could then submit a specially crafted request to upload a file.
The security update addresses the vulnerability by correcting how Windows BITS validates file names.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2020-1112?

It affects 8 products.


Products: Microsoft Windows 10, Microsoft Windows 7, Microsoft Windows 8.1, Microsoft Windows Rt 8.1, Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019.

## How do I fix CVE-2020-1112?

No fix has been published for CVE-2020-1112 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1112 being exploited?

There is no known exploitation of CVE-2020-1112 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows 10

- [CVE-2015-2426](https://insights.sbomify.com/CVE-2015-2426/): Microsoft Windows Adobe Type Manager Library Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2015-1769](https://insights.sbomify.com/CVE-2015-1769/): Microsoft Windows Mount Manager Privilege Escalation (medium 6.6, exploited in the wild)
- [CVE-2020-1467](https://insights.sbomify.com/CVE-2020-1467/): Windows Hard Link Elevation of Privilege Vulnerability (critical 10.0)
- [CVE-2021-26424](https://insights.sbomify.com/CVE-2021-26424/): Windows TCP/IP Remote Code Execution Vulnerability (critical 9.9)
- [CVE-2021-28476](https://insights.sbomify.com/CVE-2021-28476/): Windows Hyper-V Remote Code Execution Vulnerability (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-1112 and fix it if it is affected.

What it is: CVE-2020-1112 is a high-severity vulnerability in Microsoft Windows 10, published on 21 May 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-1112 in the wild and no public exploit code.

Affected product: Microsoft Windows 10. 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-2020-1112/ (Markdown: https://insights.sbomify.com/CVE-2020-1112/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1112
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1112
- OSV: https://osv.dev/vulnerability/CVE-2020-1112

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1112/
Summaries are generated and may contain mistakes; the official description above is the record.