CVE-2021-1236
MEDIUMCisco IOS XE < 17.4.1 - Unauthenticated Policy Bypass via Snort Detection Algorithm Flaw
Title source: llmDescription
Multiple Cisco products are affected by a vulnerability in the Snort application detection engine that could allow an unauthenticated, remote attacker to bypass the configured policies on an affected system. The vulnerability is due to a flaw in the detection algorithm. An attacker could exploit this vulnerability by sending crafted packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network.
References (3)
Core 3
Core References
Vendor Advisory vendor-advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-app-bypass-cSBYCATq
Third Party Advisory vendor-advisory
https://www.debian.org/security/2023/dsa-5354
Mailing List mailing-list
https://lists.debian.org/debian-lts-announce/2023/02/msg00011.html
Scores
CVSS v3
5.3
EPSS
0.0215
EPSS Percentile
79.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-670
Status
published
Products (8)
cisco/firepower_threat_defense
< 6.5.0.5
cisco/ios_xe
< 17.4.1
cisco/secure_firewall_management_center
2.9.14.0
cisco/secure_firewall_management_center
2.9.14.14
cisco/secure_firewall_management_center
2.9.15
cisco/secure_firewall_management_center
2.9.16
cisco/secure_firewall_management_center
2.9.17
snort/snort
< 2.9.14
Published
Jan 13, 2021
Tracked Since
Feb 18, 2026