CVE-2021-34749

Publication date 18 August 2021

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

A vulnerability in Server Name Identification (SNI) request filtering of Cisco Web Security Appliance (WSA), Cisco Firepower Threat Defense (FTD), and the Snort detection engine could allow an unauthenticated, remote attacker to bypass filtering technology on an affected device and exfiltrate data from a compromised host. This vulnerability is due to inadequate filtering of the SSL handshake. An attacker could exploit this vulnerability by using data from the SSL client hello packet to communicate with an external server. A successful exploit could allow the attacker to execute a command-and-control attack on a compromised host and perform additional data exfiltration attacks.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
snort	25.04 plucky	Not in release
	24.10 oracular	Not in release
	24.04 LTS noble	Not affected
	23.10 mantic	Ignored end of life, was needed
	23.04 lunar	Ignored end of life, was needs-triage
	22.10 kinetic	Ignored end of life, was needs-triage
	22.04 LTS jammy	Vulnerable
	21.10 impish	Ignored end of life
	20.04 LTS focal	Vulnerable
	18.04 LTS bionic	Vulnerable
	16.04 LTS xenial	Vulnerable
	14.04 LTS trusty	Vulnerable

Notes

yomonokio

There is no access to the actual fix for this CVE nor workarounds that address this vulnerability

Severity score breakdown

Parameter	Value
Base score	8.6 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Changed
Confidentiality	None
Integrity impact	High
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N