# CVE-2020-15117: Denial of Service in Synergy

> A remote attacker can crash the Synergy server by sending a malformed packet with an invalid client name length, causing a denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Jul 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-chfm-333q-gfpp, MGASA-2021-0040, UBUNTU-CVE-2020-15117

## What is CVE-2020-15117?

CVE-2020-15117 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 15 Jul 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

In Synergy before version 1.12.0, a Synergy server can be crashed by receiving a kMsgHelloBack packet with a client name length set to 0xffffffff (4294967295) if the servers memory is less than 4 GB. It was verified that this issue does not cause a crash through the exception handler if the available memory of the Server is more than 4GB.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions), CWE-755 (Improper Handling of Exceptional Conditions)

## Which versions are affected by CVE-2020-15117?

It affects 2 products.


Products: Fedoraproject Fedora, Symless Synergy.

## How do I fix CVE-2020-15117?

Upgrade to a fixed version.

## Is CVE-2020-15117 being exploited?

There is no known exploitation of CVE-2020-15117 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-15117 and fix it if it is affected.

What it is: CVE-2020-15117 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 15 Jul 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-15117 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2020-15117/ (Markdown: https://insights.sbomify.com/CVE-2020-15117/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-15117
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-15117
- OSV: https://osv.dev/vulnerability/CVE-2020-15117

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-15117/
Summaries are generated and may contain mistakes; the official description above is the record.