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TI-2021-13747 Aliases CVE-2021-34749GHSA-x64m-mg53-f49j

Multiple Cisco Products Server Name Identification Data Exfiltration Vulnerability

Priority MEDIUM 47CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-200.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01684 77th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco Web Security Appliance (WSA)all versions—No fix listedCNA
  • Cisco Web Security Appliance (WSA) VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:a:cisco:ironport_web_security_appliance:14.5:*:*:*:*:*:*:*14.5VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_management_center:2.9.18:*:*:*:*:*:*:*2.9.18VulnerableCisco
cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:6.6.0:*:*:*:*:*:*:*6.6.0VulnerableCisco
cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:6.7.0:*:*:*:*:*:*:*6.7.0VulnerableCisco
cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:7.0.0:*:*:*:*:*:*:*7.0.0VulnerableCisco
cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:7.1.0:*:*:*:*:*:*:*7.1.0VulnerableCisco
  • cpe:2.3:a:cisco:ironport_web_security_appliance:14.5:*:*:*:*:*:*:* Versions 14.5 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_management_center:2.9.18:*:*:*:*:*:*:* Versions 2.9.18 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:6.6.0:*:*:*:*:*:*:* Versions 6.6.0 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:6.7.0:*:*:*:*:*:*:* Versions 6.7.0 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:7.0.0:*:*:*:*:*:*:* Versions 7.0.0 Vulnerable ·Cisco
  • cpe:2.3:o:cisco:firepower_management_center_virtual_appliance_firmware:7.1.0:*:*:*:*:*:*:* Versions 7.1.0 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-34749
  2. 2026-10-03 Alias added: GHSA-x64m-mg53-f49j

References

  • TI-2019-11380 Cisco Firepower Management Center Multiple Cross-Site Scripting Vulnerabilities CVSS 3.1MEDIUM 4.8
  • TI-2019-11381 Cisco Firepower Management Center Multiple Cross-Site Scripting Vulnerabilities CVSS 3.1MEDIUM 4.8

Sources