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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | strongswan | 5.3.1-1 | — |
| Debian 13 | strongswan | 5.3.1-1 | — |
| Debian 12 | strongswan | 5.3.1-1 | — |
| Debian 8 | strongswan | 5.2.1-6+deb8u1 | DSA-3282-1 |
| Debian 7 | strongswan | 4.5.2-1.5+deb7u7 | DSA-3282-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 6.0 | strongswan | 4.4.1-5.7 | DLA-244-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | strongswan | 5.1.2-0ubuntu6 | — |
| Ubuntu 14.04 LTS | strongswan | 5.1.2-0ubuntu2.3 | USN-2628-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | strongswan | 5.1.3-18.1 | SUSE-SU-2015:1196-1 |
| SLES 11 SP4 | strongswan | 4.4.0-6.29.2 | SUSE-SU-2015:1791-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 | strongswan | 5.1.3-18.1 | SUSE-SU-2015:1196-1 |
| SLES for SAP 11 SP4 | strongswan | 4.4.0-6.29.2 | SUSE-SU-2015:1791-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | strongswan | 5.3.5-1.1 | openSUSE-SU-2024:10579-1 |
Advisories 6
- DSA-3282-1 strongswan - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-244-1 strongswan - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-2628-1 strongswan vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- openSUSE-SU-2024:10579-1 strongswan-5.3.5-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1196-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:1791-1 Security update for strongswan SUSE / openSUSE Security Updates · Feb 4, 2026
References
- 1032514 vdb-entry
- https://www.strongswan.org/blog/2015/06/08/strongswan-vulnerability-%2528cve-2015-4171%2529.html
- openSUSE-SU-2015:1082 vendor-advisory
- [oss-security] 20150608 Re: StrongSwan VPN client for Android leaks username to rouge server mailing-list
- https://www.suse.com/security/cve/CVE-2015-4171.html
- [oss-security] 20150529 StrongSwan VPN client for Android leaks username to rouge server mailing-list
- [oss-security] 20150529 Re: StrongSwan VPN client for Android leaks username to rouge server mailing-list
- https://play.google.com/store/apps/details?id=org.strongswan.android
- USN-2628-1 vendor-advisory
- DSA-3282 vendor-advisory
- 74933 vdb-entry
- https://bugzilla.suse.com/show_bug.cgi?id=933591