CVE-2021-34749 — MEDIUM (5.8)

Vulnerability 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.

CVSS Score

5.8

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Affected Products

Vendor	Product	Versions
Cisco	Ironport Web Security Appliance	14.5
Cisco	Secure Firewall Management Center	2.9.18
Cisco	Firepower Management Center Virtual Appliance Firmware	6.6.0

Related Weaknesses (CWE)

CWE-200

References

FAQ

What is CVE-2021-34749?

CVE-2021-34749 is a vulnerability with a CVSS score of 5.8 (MEDIUM). 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 unauthe...

How severe is CVE-2021-34749?

CVE-2021-34749 has been rated MEDIUM with a CVSS base score of 5.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2021-34749?

Check the references section above for vendor advisories and patch information. Affected products include: Cisco Ironport Web Security Appliance, Cisco Secure Firewall Management Center, Cisco Firepower Management Center Virtual Appliance Firmware.