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).

References;a=commitdiff;h=3984ef0b72831da8b3ece4745cac4f8575b19098;a=commitdiff;h=ea7abeeabf92b7aca160bdd0208636d4da69f4f4[email protected]/message/EWC42UXL5GHTU5G77VKBF6JYUUNGSHOM/[email protected]/message/Y3IVFGSERAZLNJCK35TEM2R4726XIH3Z/[email protected]/message/ZBEV5QGDRFUZDMNECFXUSN5FMYOZDE4V/


Source: MITRE

Published: 2018-06-12

Updated: 2019-05-30

Type: CWE-320

Risk Information

CVSS v2.0

Base Score: 5

Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P

Impact Score: 2.9

Exploitability Score: 10

Severity: MEDIUM

CVSS v3.0

Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Impact Score: 3.6

Exploitability Score: 3.9

Severity: HIGH