# CVE-2020-13699: Command injection in n/a

> Attackers can exploit improper URI quoting to force NTLM authentication requests, enabling hash capture or relay attacks against TeamViewer users.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 29 Jul 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-f43w-mfrf-mv66

## What is CVE-2020-13699?

CVE-2020-13699 is a high-severity command injection vulnerability in n/a, published on 29 Jul 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

TeamViewer Desktop for Windows before 15.8.3 does not properly quote its custom URI handlers. A malicious website could launch TeamViewer with arbitrary parameters, as demonstrated by a teamviewer10: --play URL. An attacker could force a victim to send an NTLM authentication request and either relay the request or capture the hash for offline password cracking. This affects teamviewer10, teamviewer8, teamviewerapi, tvchat1, tvcontrol1, tvfiletransfer1, tvjoinv8, tvpresent1, tvsendfile1, tvsqcustomer1, tvsqsupport1, tvvideocall1, and tvvpn1. The issue is fixed in 8.0.258861, 9.0.258860, 10.0.258873, 11.0.258870, 12.0.258869, 13.2.36220, 14.2.56676, 14.7.48350, and 15.8.3.

Weakness: CWE-88 (Improper Neutralization of Argument Delimiters in a Command)

## Which versions are affected by CVE-2020-13699?

It affects 1 product.


Products: Teamviewer Teamviewer.

## How do I fix CVE-2020-13699?

No fix has been published for CVE-2020-13699 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-13699 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-13699 exists.

Public exploit code:

- https://github.com/Dilshan-Eranda/CVE-2020-13699 (github_poc): https://github.com/Dilshan-Eranda/CVE-2020-13699
- TeamViewer Unquoted URI Handler SMB Redirect (metasploit)

## Other vulnerabilities in n/a

- [CVE-2019-18988](https://insights.sbomify.com/CVE-2019-18988/): TeamViewer Desktop Bypass Remote Login (high 7.0, exploited in the wild)
- [CVE-2018-16550](https://insights.sbomify.com/CVE-2018-16550/): Security feature bypass in n/a (critical 9.8)
- [CVE-2010-3128](https://insights.sbomify.com/CVE-2010-3128/): Path traversal in n/a (critical 9.3)
- [CVE-2018-14333](https://insights.sbomify.com/CVE-2018-14333/): Information disclosure in n/a (high 8.1)
- [CVE-2021-34858](https://insights.sbomify.com/CVE-2021-34858/): Memory corruption in TeamViewer (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-13699 and fix it if it is affected.

What it is: CVE-2020-13699 is a high-severity command injection vulnerability in n/a, published on 29 Jul 2020. An attacker can exploit it over the internet without logging in, 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-2020-13699 exists.

Affected product: n/a. 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-2020-13699/ (Markdown: https://insights.sbomify.com/CVE-2020-13699/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-13699
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-13699
- OSV: https://osv.dev/vulnerability/CVE-2020-13699

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-13699/
Summaries are generated and may contain mistakes; the official description above is the record.