CVE-2018-0732
CVSS v3
7.5
HIGH
EPSS Score
48.8 %
exploit probability, as of 2026-10-08
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2-1.0.2o).
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2018-06-12
- Last Modified
- 2026-10-08
Frequently asked questions
What is CVE-2018-0732?
During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2-1.0.2o).
Is CVE-2018-0732 actively exploited?
Active exploitation of CVE-2018-0732 has not been confirmed. Its EPSS score was 48.8% on 2026-10-08, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2018-0732?
CVE-2018-0732 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
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