NVD

NOTICE UPDATED - April, 25th 2024

NIST has updated the NVD program announcement page with additional information regarding recent concerns and the temporary delays in enrichment efforts.

CVE-2021-34749 Detail

Modified

This vulnerability has been modified since it was last analyzed by the NVD. It is awaiting reanalysis which may result in further changes to the information provided.

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.

Severity

CVSS 4.0 Severity and Metrics:

NIST: NVD

N/A

NVD assessment not yet provided.

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

CVSS 3.x Severity and Metrics:

NIST: NVD

Base Score: 8.6 HIGH

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Nist CVSS score does not match with CNA score

CNA: Cisco Systems, Inc.

Base Score: 5.8 MEDIUM

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

CVSS 2.0 Severity and Metrics:

National Institute of Standards and Technology

NIST: NVD

Base Score: 5.0 MEDIUM

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

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

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Hyperlink	Resource
https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sni-data-exfil-mFgzXqLN	Patch Vendor Advisory
https://www.debian.org/security/2023/dsa-5354

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-200	Exposure of Sensitive Information to an Unauthorized Actor	NIST Cisco Systems, Inc.

Known Affected Software Configurations Switch to CPE 2.2

CPEs loading, please wait.

Denotes Vulnerable Software
Are we missing a CPE here? Please let us know.

Change History

5 change records found show changes

Initial Analysis by NIST 8/25/2021 3:11:04 PM

Action	Type	Old Value	New Value
Added	CPE Configuration		Record truncated, showing 500 of 534 characters. View Entire Change Record 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_appl
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
Added	CWE		NIST CWE-200
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

Quick Info

CVE Dictionary Entry:
CVE-2021-34749
NVD Published Date:
08/18/2021
NVD Last Modified:
11/06/2023
Source:
Cisco Systems, Inc.

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Information Technology Laboratory

National Vulnerability Database

National Vulnerability Database

CVE-2021-34749 Detail

Description

Severity

References to Advisories, Solutions, and Tools

Weakness Enumeration

Known Affected Software Configurations Switch to CPE 2.2

CPEs loading, please wait.

Change History

CVE Modified by Cisco Systems, Inc. 5/14/2024 5:15:11 AM

CVE Modified by Cisco Systems, Inc. 11/06/2023 10:36:18 PM

CVE Modified by Cisco Systems, Inc. 2/18/2023 11:15:12 PM

CVE Modified by Cisco Systems, Inc. 2/10/2023 9:20:43 PM

Initial Analysis by NIST 8/25/2021 3:11:04 PM

Quick Info