Multiple Cisco products are affected by a vulnerability in 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 handling of an HTTP range header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an affected device. A successful exploit could allow the attacker to bypass configured file policy for HTTP packets and deliver a malicious payload.
CVE-2021-1223
HIGHCVSS 7.5
7.5
- CVSS v3
- 7.5
- EG Score
- —
- EPSS
- —
- KEV
- Not listed
Published
January 13, 2021
Last Modified
November 26, 2024
References (6)
- psirt@ciscohttps://lists.debian.org/debian-lts-announce/2023/02/msg00011.html
- psirt@ciscohttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-filepolbypass-67DEwMe2
- psirt@ciscohttps://www.debian.org/security/2023/dsa-5354
- af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html
- af854a3a-2127-422b-91ae-364da2661108https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-filepolbypass-67DEwMe2
- af854a3a-2127-422b-91ae-364da2661108https://www.debian.org/security/2023/dsa-5354
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× in last 30d)
Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.
- 2026-05-27 13:39 UTCepss_batch
- 2026-05-26 22:06 UTCEG score recompute
- 2026-05-26 22:06 UTCGHSA enrichment
- 2026-05-26 13:42 UTCepss_batch
- 2026-05-26 13:42 UTCepss_batch
- 2026-05-26 07:17 UTCepss_batch
- 2026-05-26 07:17 UTCepss_batch
- 2026-05-24 21:12 UTCOSV refresh
- 2026-05-24 16:49 UTCepss_batch
Frequently asked(4)
What is CVE-2021-1223?
CVE-2021-1223 is a high vulnerability published on January 13, 2021. Multiple Cisco products are affected by a vulnerability in 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 handling of an HTTP range header. An attacker could exploit this…
When was CVE-2021-1223 disclosed?
CVE-2021-1223 was first published in the National Vulnerability Database on January 13, 2021, with the most recent update on November 26, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2021-1223?
CVE-2021-1223 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2021-1223?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1223, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-1223
Is Your Infrastructure Affected by CVE-2021-1223?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.