CVE Catalog

CVE-2021-40116

HighCVSS 8.6
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Elevated risk
1.35%

69th percentile - higher than 69% of all known CVEs

Summary

A vulnerability in Snort rules in multiple Cisco products could allow an unauthenticated, remote attacker to cause a denial of service (DoS). The issue is due to improper handling of Block with Reset or Interactive Block with Reset actions if a rule is configured without proper constraints. Exploitation involves sending a crafted IP packet.

Risk Assessment

Exploitation could cause traffic to be dropped, leading to network disruption and potential service unavailability.

Recommendation

Update to patched Cisco software and review Snort3 rule configurations to ensure proper constraints.

Other vulnerabilities in Snort

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS