Instituto Nacional de ciberseguridad. Sección Incibe
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CVE-2021-40116

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
27/10/2021
Last modified:
07/07/2025

Description

Multiple Cisco products are affected by a vulnerability in Snort rules that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.The vulnerability is due to improper handling of the Block with Reset or Interactive Block with Reset actions if a rule is configured without proper constraints. An attacker could exploit this vulnerability by sending a crafted IP packet to the affected device. A successful exploit could allow the attacker to cause through traffic to be dropped. Note: Only products with Snort3 configured and either a rule with Block with Reset or Interactive Block with Reset actions configured are vulnerable. Products configured with Snort2 are not vulnerable.

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.60 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
8.60
Severity 3.x
HIGH
Vector 2.0
AV:N/AC:M/Au:N/C:N/I:N/A:C CVSS v2.0 Severity and Metrics:

Base Score: 7.10 HIGH
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C

Attack Vector (AV): Network
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): None
Integrity (I): None
Availability (A): Complete

Base Score 2.0
7.10
Severity 2.0
HIGH

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* 6.4.0 (including) 6.4.0.13 (excluding)
cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* 6.6.0 (including) 6.6.5.1 (excluding)
cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* 6.7.0 (including) 6.7.0.3 (excluding)
cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* 7.0.0 (including) 7.0.1 (excluding)
cpe:2.3:a:cisco:secure_firewall_management_center:3.1.0.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:snort:*:*:*:*:*:*:*:* 3.0.0.0 (including) 3.1.0.100 (excluding)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools