CVE-2018-0732 - CVE House
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Status published High CVE-2018-0732

Client DoS due to large DH parameter

Vulnerability 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).

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Guido Vranken

References

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Affected Vendor

Affected Software

OpenSSL
Vulnerable Versions:
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)

Timeline

Official Publish: June 12th, 2018
Last Modified: September 17th, 2024
Added to House: July 20th, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.