CVE-2021-34749
"Cisco SNI Bypass: Remote Attack Allowance through Inadequate SSL Handshake Filtering"
Description
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.
INFO
Published Date :
Aug. 18, 2021, 8:15 p.m.
Last Modified :
Nov. 7, 2023, 3:36 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
4.0
Exploitability Score :
3.9
Affected Products
The following products are affected by CVE-2021-34749
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-34749.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-34749 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-34749 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Nov. 07, 2023
Action Type Old Value New Value Removed CVSS V3 Cisco Systems, Inc. AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N Added CVSS V3.1 Cisco Systems, Inc. AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N -
CVE Modified by [email protected]
Feb. 19, 2023
Action Type Old Value New Value Added Reference https://www.debian.org/security/2023/dsa-5354 [No Types Assigned] -
CVE Modified by [email protected]
Feb. 11, 2023
Action Type Old Value New Value Added Reference https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html [No Types Assigned] -
Initial Analysis by [email protected]
Aug. 25, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:P/A:N) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N Changed Reference Type https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sni-data-exfil-mFgzXqLN No Types Assigned https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sni-data-exfil-mFgzXqLN Patch, Vendor Advisory Added CWE NIST CWE-200 Added CPE Configuration OR *cpe:2.3:a:cisco:firepower_management_center:2.9.18:*:*:*:*:*:*:* *cpe:2.3:a:cisco:ironport_web_security_appliance:14.5:*:*:*:*:*:*:* *cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:6.6.0:*:*:*:*:*:*:* *cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:6.7.0:*:*:*:*:*:*:* *cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:7.0.0:*:*:*:*:*:*:* *cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:7.1.0:*:*:*:*:*:*:*
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-34749 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-34749
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.26 }} 0.03%
score
0.65234
percentile