CVE intelligence and bounded remediation

CVE-2018-5389 — The Internet Key Exchange v1 main mode is vulnerable to offline dictionary or brute force attacks

Medium CVSS 5.9

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.

Severity
Medium
CVSS
5.9 (3.0)
Published
2018-09-06
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-521

Affected products

  • ietf / internet_key_exchange / 1.0

Matched remediation archetype

Authentication bypass and missing authentication

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Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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