CVE-2021-1224

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    CVE-2021-1224

    Published: 13 Jan 2021Last Modified: 10 Mar 2026

    Summary:

    Details: 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.

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

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2021-1224 | CVE-DB