CVE-2021-1224

Multiple Cisco products are affected by a vulnerability with TCP Fast Open (TFO) when used in conjunction with the Snort detection engine that could allow an unauthenticated, remote attacker to bypass a configured file policy for HTTP. The vulnerability is due to incorrect detection of the HTTP payload if it is contained at least partially within the TFO connection handshake. An attacker could exploit this vulnerability by sending crafted TFO packets with an HTTP payload through an affected device. A successful exploit could allow the attacker to bypass configured file policy for HTTP packets and deliver a malicious payload.

• CWE-693

• https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-tfo-bypass-MmzZrtesVendor Advisory
• https://www.debian.org/security/2023/dsa-5354
• https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-tfo-bypass-MmzZrtesVendor Advisory
• https://www.debian.org/security/2023/dsa-5354

Published

Jan 13, 2021

Last Modified

Aug 11, 2026

Status

Modified

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