CVE-2017-3733

Publication date 4 May 2017

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
openssl	16.10 yakkety	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
	12.04 LTS precise	Not affected
openssl098	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not affected

Notes

mdeslaur

only affects 1.1.x

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

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