CVE-2018-0732
openssl: Malicious server can send large prime to client during DH(E) TLS handshake causing the client to hang
Severity
ModerateRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · June 12, 2018
Updated · October 9, 2026
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).
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.0 · 4.3CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
CWE-325 · Missing Cryptographic Step