Vulnerability in Cisco 1100-4p Integrated Services Router
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.
EPSS: 0.020 (78.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N.
Affected products
- Cisco 1100-4p_integrated_services_router
- Cisco 1100-8p_integrated_services_router
- Cisco 1101-4p_integrated_services_router
- Cisco 1109-2p_integrated_services_router
- Cisco 1109-4p_integrated_services_router
- Cisco 1111x-8p_integrated_services_router
- Cisco 4221_integrated_services_router
- Cisco 4321_integrated_services_router
- Cisco 4331_integrated_services_router
- Cisco 4351_integrated_services_router
Weakness classification (CWE)
Public proof-of-concept exploits
References
- psirt@cisco.com (vendor-advisory, Vendor Advisory)
- psirt@cisco.com (mailing-list)
- psirt@cisco.com (vendor-advisory)
Frequently asked questions
- What is CVE-2021-1224?
- CVE-2021-1224 is a medium-severity vulnerability in Cisco 1100-4p Integrated Services Router, classified under Protection Mechanism Failure. CVSS score: 5.8/10. Published 2021-01-13.
- How severe is CVE-2021-1224?
- Medium severity. CVSS v3 base score is 5.8 out of 10.
- Is CVE-2021-1224 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.