CVEvulnerability
CVE-2021-34749
8.6 HIGH
Official page ↗
- Status
- Modified
- Published
- 2021-08-18
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.8 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- CVSS 3.1 ([email protected])
- 8.6 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
- CVSS 2.0 ([email protected])
- 5.0 MEDIUM — AV:N/AC:L/Au:N/C:N/I:P/A:N
- Weaknesses
- CWE-200
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.
Affected configurations
• 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
• cisco firepower management center virtual appliance firmware 6.7.0
• cisco firepower management center virtual appliance firmware 7.0.0
• cisco firepower management center virtual appliance firmware 7.1.0
Related
Weakness · CWE (1)
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor weakness
References
- https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html lists.debian.org
- 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 www.debian.org
- https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html lists.debian.org
- 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 www.debian.org