CVE-2021-1224

MEDIUM

Cisco Snort TFO - HTTP File Policy Bypass via TCP Fast Open Payload

Title source: manual
STIX 2.1

Description

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.

Scores

CVSS v3 5.8
EPSS 0.0065
EPSS Percentile 71.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-693
Status published
Products (21)
cisco/firepower_threat_defense < 6.7.0
cisco/ios_xe < 17.4.1
cisco/meraki_mx100_firmware
cisco/meraki_mx250_firmware
cisco/meraki_mx450_firmware
cisco/meraki_mx64_firmware
cisco/meraki_mx64w_firmware
cisco/meraki_mx67_firmware
cisco/meraki_mx67c_firmware
cisco/meraki_mx67w_firmware
... and 11 more
Published Jan 13, 2021
Tracked Since Feb 18, 2026