Vulnerability identifier: #VU13325

Vulnerability risk: Low

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-0732

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to improper handling of large prime values by the affected software during key agreement operations in a Transport Layer Security (TLS) handshake using an Ephemeral Diffie-Hellman (DHE) based cipher suite. A remote attacker can send a large prime value from a malicious OpenSSL server to a targeted OpenSSL client and cause the client to stop responding while generating a key for the prime value.

Mitigation
Update to versions 1.1.0i or 1.0.2p.

Vulnerable software versions

OpenSSL: 1.1.0 - 1.1.0h, 1.0.2 - 1.0.2o

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External links
http://www.openssl.org/news/secadv/20180612.txt

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.