SSL 64-bit Block Size Cipher Suites Supported (SWEET32)

medium Nessus Plugin ID 94437
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VPR Score: 4.4

Synopsis

The remote service supports the use of 64-bit block ciphers.

Description

The remote host supports the use of a block cipher with 64-bit blocks in one or more cipher suites. It is, therefore, affected by a vulnerability, known as SWEET32, due to the use of weak 64-bit block ciphers. A man-in-the-middle attacker who has sufficient resources can exploit this vulnerability, via a 'birthday' attack, to detect a collision that leaks the XOR between the fixed secret and a known plaintext, allowing the disclosure of the secret text, such as secure HTTPS cookies, and possibly resulting in the hijacking of an authenticated session.

Proof-of-concepts have shown that attackers can recover authentication cookies from an HTTPS session in as little as 30 hours.

Note that the ability to send a large number of requests over the same TLS connection between the client and server is an important requirement for carrying out this attack. If the number of requests allowed for a single connection were limited, this would mitigate the vulnerability. This plugin requires report paranoia as Nessus has not checked for such a mitigation.

Solution

Reconfigure the affected application, if possible, to avoid use of all 64-bit block ciphers. Alternatively, place limitations on the number of requests that are allowed to be processed over the same TLS connection to mitigate this vulnerability.

See Also

https://sweet32.info

https://www.openssl.org/blog/blog/2016/08/24/sweet32/

Plugin Details

Severity: Medium

ID: 94437

File Name: ssl_64bitblock_supported_ciphers.nasl

Version: 1.12

Type: remote

Family: General

Published: 11/1/2016

Updated: 2/3/2021

Dependencies: ssl_supported_ciphers.nasl

Configuration: Enable paranoid mode

Risk Information

Risk Factor: Medium

VPR Score: 4.4

CVSS Score Source: CVE-2016-2183

CVSS v2.0

Base Score: 5

Temporal Score: 3.9

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

Temporal Vector: E:POC/RL:OF/RC:C

CVSS v3.0

Base Score: 7.5

Temporal Score: 6.7

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

Temporal Vector: E:P/RL:O/RC:C

Vulnerability Information

Required KB Items: Settings/ParanoidReport

Exploit Available: true

Exploit Ease: Exploits are available

Vulnerability Publication Date: 8/24/2016

Reference Information

CVE: CVE-2016-2183, CVE-2016-6329

BID: 92630, 92631