SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-40116

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…

HIGH 7.5EPSS 1.39%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.39% probability · 71th percentile
CISA KEV
Not listed
Weakness
CWE-241
Affected
cisco/secure firewall management center · cisco/secure firewall threat defense · cisco/snort
Source
psirt@cisco.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.