# CVE-2020-17144: Microsoft Exchange Server Remote Code Execution

> Attackers can execute arbitrary code on Microsoft Exchange Server via a deserialization vulnerability, requiring immediate patching.

- **Severity:** High 8.4 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C`)
- **Exploited in the wild:** Yes, since 3 Nov 2021 (CISA KEV)
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Dec 2020
- **Updated:** 9 Jun 2026
- **Also known as:** GHSA-68q4-hg7f-7p9c

## What is CVE-2020-17144?

CVE-2020-17144 is a high-severity unsafe deserialization vulnerability in Microsoft Exchange Server, published on 9 Dec 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Microsoft Exchange Remote Code Execution Vulnerability

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2020-17144?

It affects 1 product.


Products: Microsoft Exchange Server.

## How do I fix CVE-2020-17144?

No fix has been published for CVE-2020-17144 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

## Is CVE-2020-17144 being exploited?

Yes. Attackers have exploited CVE-2020-17144 in the wild since at least 3 Nov 2021.

Public exploit code:

- weaponized tool for CVE-2020-17144 (github_poc): https://github.com/zcgonvh/CVE-2020-17144
- Exchange2010 authorized RCE (github_poc): https://github.com/Airboi/CVE-2020-17144-EXP

## Other vulnerabilities in Microsoft Exchange Server

- [CVE-2024-21410](https://insights.sbomify.com/CVE-2024-21410/): Microsoft Exchange Server Privilege Escalation (critical 9.8, exploited in the wild)
- [CVE-2021-34473](https://insights.sbomify.com/CVE-2021-34473/): Microsoft Exchange Server Remote Code Execution (critical 9.1, exploited in the wild)
- [CVE-2021-26855](https://insights.sbomify.com/CVE-2021-26855/): Microsoft Exchange Server Remote Code Execution (critical 9.1, exploited in the wild)
- [CVE-2021-34523](https://insights.sbomify.com/CVE-2021-34523/): Microsoft Exchange Server Privilege Escalation (critical 9.0, exploited in the wild)
- [CVE-2023-21529](https://insights.sbomify.com/CVE-2023-21529/): Microsoft Exchange Server Deserialization of Untrusted Data (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-17144 and fix it if it is affected.

What it is: CVE-2020-17144 is a high-severity unsafe deserialization vulnerability in Microsoft Exchange Server, published on 9 Dec 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: Yes. Attackers have exploited CVE-2020-17144 in the wild since at least 3 Nov 2021.

Affected product: Microsoft Exchange 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-2020-17144/ (Markdown: https://insights.sbomify.com/CVE-2020-17144/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-17144
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-17144
- OSV: https://osv.dev/vulnerability/CVE-2020-17144

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-17144/
Summaries are generated and may contain mistakes; the official description above is the record.