Medium severity5.3NVD Advisory· Published Jan 13, 2021· Updated Aug 11, 2026

CVE-2021-1236

Description

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

Cisco Systems, Inc./Secure Firewall Management Center5 versions
cpe:2.3:a:cisco:secure_firewall_management_center:2.9.14.0:*:*:*:*:*:*:*+ 4 more
- cpe:2.3:a:cisco:secure_firewall_management_center:2.9.14.0:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:secure_firewall_management_center:2.9.14.14:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:secure_firewall_management_center:2.9.15:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:secure_firewall_management_center:2.9.16:*:*:*:*:*:*:*
- cpe:2.3:a:cisco:secure_firewall_management_center:2.9.17:*:*:*:*:*:*:*
Cisco Systems, Inc./Secure Firewall Threat Defense
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
Range: <6.5.0.5
Snort/Snort
cpe:2.3:a:snort:snort:*:*:*:*:*:*:*:*
Range: <2.9.14
Cisco Systems, Inc./iOS Xe
cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*
Range: <17.4.1
Cisco Systems, Inc./Snortllm-fuzzy
Cisco Systems, Inc./Firepower Threat Defense Softwarecpe-rescue
Range: n/a

cvss	0.345
epss	0.002
exploit	0.000
kev	0.000
patch	0.000
ransomware	0.000

CVE-2021-1236

Description

AI Insight

Affected products

Patches

Vulnerability mechanics

References

News mentions