SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

HIGH 7.5EPSS 48.8%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 48.8%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.

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 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
48.83% probability · 99th percentile
CISA KEV
Not listed
Weakness
CWE-320
Affected
openssl/openssl · canonical/ubuntu linux · debian/debian linux · nodejs/node.js
Source
openssl-security@openssl.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.