# CVE-2020-1493: Microsoft Outlook Information Disclosure Vulnerability

> An attacker can share attached files via email links, allowing unauthorized anonymous access to restricted data in Microsoft Outlook.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **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:** 17 Aug 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-w39r-2vjm-hgjq

## What is CVE-2020-1493?

CVE-2020-1493 is a medium-severity vulnerability in Microsoft 365 Apps, published on 17 Aug 2020. 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

An information disclosure vulnerability exists when attaching files to Outlook messages. This vulnerability could potentially allow users to share attached files such that they are accessible by anonymous users where they should be restricted to specific users.
To exploit this vulnerability, an attacker would have to attach a file as a link to an email. The email could then be shared with individuals that should not have access to the files, ignoring the default organizational setting.
The security update addresses the vulnerability by correcting how Outlook handles file attachment links.

Weakness: CWE-922 (Insecure Storage of Sensitive Information)

## Which versions are affected by CVE-2020-1493?

It affects 3 products.


Products: Microsoft 365 Apps, Microsoft Office, Microsoft Outlook.

## How do I fix CVE-2020-1493?

No fix has been published for CVE-2020-1493 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-1493 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-1493 exists.

Public exploit code:

- https://github.com/0neb1n/CVE-2020-1493 (github_poc): https://github.com/0neb1n/CVE-2020-1493

## Other vulnerabilities in Microsoft 365 Apps

- [CVE-2024-21413](https://insights.sbomify.com/CVE-2024-21413/): Microsoft Outlook Improper Input Validation (critical 9.8, exploited in the wild)
- [CVE-2023-23397](https://insights.sbomify.com/CVE-2023-23397/): Microsoft Office Outlook Privilege Escalation (critical 9.8, exploited in the wild)
- [CVE-2024-38189](https://insights.sbomify.com/CVE-2024-38189/): Microsoft Project Remote Code Execution Vulnerability (high 8.8, exploited in the wild)
- [CVE-2023-35311](https://insights.sbomify.com/CVE-2023-35311/): Microsoft Outlook Security Feature Bypass (high 8.8, exploited in the wild)
- [CVE-2026-21514](https://insights.sbomify.com/CVE-2026-21514/): Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-1493 and fix it if it is affected.

What it is: CVE-2020-1493 is a medium-severity vulnerability in Microsoft 365 Apps, published on 17 Aug 2020. 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-2020-1493 exists.

Affected product: Microsoft 365 Apps. 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-2020-1493/ (Markdown: https://insights.sbomify.com/CVE-2020-1493/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1493
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1493
- OSV: https://osv.dev/vulnerability/CVE-2020-1493

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1493/
Summaries are generated and may contain mistakes; the official description above is the record.