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Fencer Intel
low 2.6

CVE-2015-4171 json

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 I…

published 11y ago modified 4mo ago also EUVD-2015-4194

cvss
2.6
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.0%
EPSS 2.0% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

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.

Patch / fix

  • strongswan Debian 14, Debian 13, Debian 12 5.3.1-1

debian advisories DEBIAN-CVE-2015-4171

  • strongswan Ubuntu 14.04 LTS 5.1.2-0ubuntu2.3
  • strongswan Ubuntu 16.04 LTS 5.1.2-0ubuntu6

ubuntu advisories UBUNTU-CVE-2015-4171

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • strongswan SLES for SAP 11 SP4, SLES 11 SP4 4.4.0-6.29.2
  • strongswan SLES for SAP 12, SLES 12, SLED 12 5.1.3-18.1

suse advisories SUSE-SU-2015:1791-1SUSE-SU-2015:1196-1

  • strongswan openSUSE Tumbleweed 5.3.5-1.1

opensuse advisories openSUSE-SU-2024:10579-1

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-4171 updated cvss 1.4

strongswan: rogue servers are able to gain user credentials from a client in certain IKEv2 setups

  • Red Hat Enterprise Linux 7 strongimcv
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.03% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 2.6 AV:N/AC:H/Au:N/C:P/I:N/A:N

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.