# CVE-2020-1025: Microsoft Office Elevation of Privilege Vulnerability

> Attackers can bypass authentication and gain improper access by modifying OAuth tokens in SharePoint and Skype for Business servers.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jul 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-5xrx-pfvm-p5p8

## What is CVE-2020-1025?

CVE-2020-1025 is a critical authentication bypass vulnerability in Microsoft Sharepoint Enterprise Server, published on 14 Jul 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An elevation of privilege vulnerability exists when Microsoft SharePoint Server and Skype for Business Server improperly handle OAuth token validation. An attacker who successfully exploited the vulnerability could bypass authentication and achieve improper access.
To exploit this vulnerability, an attacker would need to modify the token.
The update addresses the vulnerability by modifying how Microsoft SharePoint Server and Skype for Business Server validate tokens.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-1025?

It affects 5 products.


Products: Microsoft Lync, Microsoft Sharepoint Enterprise Server, Microsoft Sharepoint Foundation, Microsoft Sharepoint Server, Microsoft Skype for Business.

## How do I fix CVE-2020-1025?

No fix has been published for CVE-2020-1025 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1025 being exploited?

There is no known exploitation of CVE-2020-1025 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Sharepoint Enterprise Server

- [CVE-2013-1302](https://insights.sbomify.com/CVE-2013-1302/): Use after free in n/a (critical 9.3)
- [CVE-2012-1849](https://insights.sbomify.com/CVE-2012-1849/): Path traversal in n/a (critical 9.3)
- [CVE-2018-8311](https://insights.sbomify.com/CVE-2018-8311/): Code injection in Microsoft Lync (high 8.8)
- [CVE-2017-11786](https://insights.sbomify.com/CVE-2017-11786/): Auth bypass in Skype for Business (high 8.8)
- [CVE-2017-0283](https://insights.sbomify.com/CVE-2017-0283/): Memory corruption in Uniscribe (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-1025 and fix it if it is affected.

What it is: CVE-2020-1025 is a critical authentication bypass vulnerability in Microsoft Sharepoint Enterprise Server, published on 14 Jul 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-1025 in the wild and no public exploit code.

Affected product: Microsoft Sharepoint Enterprise Server. 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-2020-1025/ (Markdown: https://insights.sbomify.com/CVE-2020-1025/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1025
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1025
- OSV: https://osv.dev/vulnerability/CVE-2020-1025

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-1025/
Summaries are generated and may contain mistakes; the official description above is the record.