# CVE-2017-8535: Denial of service in Malware Protection Engine

> Attackers can cause a denial of service in Microsoft Malware Protection Engine by submitting specially crafted files, affecting Windows and Exchange servers.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 26 May 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-h2pr-84p4-xhj2

## What is CVE-2017-8535?

CVE-2017-8535 is a medium-severity denial of service vulnerability in Microsoft Exchange Server, published on 26 May 2017. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, and Windows Server 2016, Microsoft Exchange Server 2013 and 2016, does not properly scan a specially crafted file leading to denial of service. aka "Microsoft Malware Protection Engine Denial of Service Vulnerability", a different vulnerability than CVE-2017-8536, CVE-2017-8537, CVE-2017-8539, and CVE-2017-8542.

Weakness: CWE-674 (Uncontrolled Recursion), CWE-476 (NULL Pointer Dereference), CWE-369 (Divide By Zero), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2017-8535?

It affects 7 products.


Products: Microsoft Endpoint Protection, Microsoft Exchange Server, Microsoft Forefront Endpoint Protection, Microsoft Security Essentials, Microsoft System Center Endpoint Protection, Microsoft Windows Defender, Microsoft Windows Intune Endpoint Protection.

## How do I fix CVE-2017-8535?

No fix has been published for CVE-2017-8535 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-8535 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-8535 exists.

Public exploit code:

- Microsoft MsMpEng - Multiple Crashes While Scanning Malformed Files (exploitdb)

## Other vulnerabilities in Microsoft Exchange Server

- [CVE-2017-8540](https://insights.sbomify.com/CVE-2017-8540/): Microsoft Malware Protection Engine Improper Restriction of Operations (high 7.8, exploited in the wild)
- [CVE-2021-24092](https://insights.sbomify.com/CVE-2021-24092/): Microsoft Defender Elevation of Privilege Vulnerability (high 7.8)
- [CVE-2017-8558](https://insights.sbomify.com/CVE-2017-8558/): Memory corruption in Microsoft Malware Protection Engine (high 7.8)
- [CVE-2017-8536](https://insights.sbomify.com/CVE-2017-8536/): Denial of service in Malware Protection Engine (medium 5.5)
- [CVE-2017-8537](https://insights.sbomify.com/CVE-2017-8537/): Denial of service in Malware Protection Engine (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-8535 and fix it if it is affected.

What it is: CVE-2017-8535 is a medium-severity denial of service vulnerability in Microsoft Exchange Server, published on 26 May 2017. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-8535 exists.

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-2017-8535/ (Markdown: https://insights.sbomify.com/CVE-2017-8535/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-8535
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-8535
- OSV: https://osv.dev/vulnerability/CVE-2017-8535

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-8535/
Summaries are generated and may contain mistakes; the official description above is the record.