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Fencer Vulns
medium 5.9

CVE-2018-5389 json

CVE-2018-5389

published 2018-09-06 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-17159

cvss
5.9
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.1%
EPSS 3.1% chance of exploitation in 30 days, percentile 87%
public exploits
0
none known

Summary

The Internet Key Exchange v1 main mode is vulnerable to offline dictionary or brute force attacks. Reusing a key pair across different versions and modes of IKE could lead to cross-protocol authentication bypasses. It is well known, that the aggressive mode of IKEv1 PSK is vulnerable to offline dictionary or brute force attacks. For the main mode, however, only an online attack against PSK authentication was thought to be feasible. This vulnerability could allow an attacker to recover a weak Pre-Shared Key or enable the impersonation of a victim host or network.

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-2018-5389 updated cvss 5.9

IKEv1: IKEv1 protocol vulnerability in the authentication mode with pre-shared keys in the main mode of operation

  • Red Hat Enterprise Linux 5 openswan, ipsec-tools Red Hat Enterprise Linux 6 openswan, libreswan Red Hat Enterprise Linux 7 libreswan Red Hat Enterprise Linux 8 libreswan
    affected: no fix planned “Will not fix”

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

3.09% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • web-in-security.blogspot.com https://web-in-security.blogspot.com/2018/08/practical-dictionary-attack-on-ipsec-ike.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Affected products

  • strongSwan Strongswan

Classification

Weakness
  • CWE-521 Weak Password Requirements

References

Sources

Fencer Vulns 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.