CVE-2018-5389
The Internet Key Exchange v1 main mode is vulnerable to offline dictionary or brute force attacks.
Does this matter?
Lower severity and a low EPSS score (3.06%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.0
- 5.9 MEDIUMCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 3.06% probability · 88th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-521
- Affected
- ietf/internet key exchange
- Source
- cret@cert.org
EPSS 3.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://blogs.cisco.com/security/great-cipher-but-where-did-you-get-that-keyThird Party Advisory
- https://my.f5.com/manage/s/article/K42378447
- https://web-in-security.blogspot.com/2018/08/practical-dictionary-attack-on-ipsec-ike.htmlExploit, Third Party Advisory
- https://www.kb.cert.org/vuls/id/857035Third Party Advisory, US Government Resource
- https://www.usenix.org/system/files/conference/usenixsecurity18/sec18-felsch.pdfThird Party Advisory
- https://blogs.cisco.com/security/great-cipher-but-where-did-you-get-that-keyThird Party Advisory
- https://my.f5.com/manage/s/article/K42378447
- https://web-in-security.blogspot.com/2018/08/practical-dictionary-attack-on-ipsec-ike.htmlExploit, Third Party Advisory
- https://www.kb.cert.org/vuls/id/857035Third Party Advisory, US Government Resource
- https://www.usenix.org/system/files/conference/usenixsecurity18/sec18-felsch.pdfThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.