cisco firepower-management-center CVE-2021-40116 in Cisco and Snort Products
Published on October 27, 2021

Multiple Cisco Products Snort Rule Denial of Service Vulnerability

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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.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2021-40116 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

Improper Handling of Unexpected Data Type

The software does not handle or incorrectly handles when a particular element is not the expected type, e.g. it expects a digit (0-9) but is provided with a letter (A-Z).


Products Associated with CVE-2021-40116

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2021-40116 are published in these products:

Cisco Firepower Management Center
 
Cisco Firepower Threat Defense
 
Snort
 
Cisco Secure Firewall Management Center
 
Cisco Snort
 

Affected Versions

Cisco Firepower Threat Defense Software Version n/a is affected by CVE-2021-40116

Exploit Probability

EPSS
0.78%
Percentile
73.42%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.