CVE-2024-20330 | Cisco Firepower Threat Defense Software for Cisco Firepower 2100 Series TCP UDP Snort 2 and Snort 2 Denial of Service Vulnerability

A vulnerability in the Snort 2 and Snort 3 TCP and UDP detection engine of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Appliances could allow an unauthenticated, remote attacker to cause memory corruption, which could cause the Snort detection engine to restart unexpectedly. This vulnerability is due to improper memory management when the Snort detection engine processes specific TCP or UDP packets. An attacker could exploit this vulnerability by sending crafted TCP or UDP packets through a device that is inspecting traffic using the Snort detection engine. A successful exploit could allow the attacker to restart the Snort detection engine repeatedly, which could cause a denial of service (DoS) condition. The DoS condition impacts only the traffic through the device that is examined by the Snort detection engine. The device can still be managed over the network. Note: Once a memory block is corrupted, it cannot be cleared until the Cisco Firepower 2100 Series Appliance is manually reloaded. This means that the Snort detection engine could crash repeatedly, causing traffic that is processed by the Snort detection engine to be dropped until the device is manually reloaded.

Published: 2024-10-23 Last update: 2025-08-06 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2024-20330 is rated Moderate Risk (53.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.32%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-20330

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-16 0.19% 0.32% +0.13%
2 2025-12-01 0.15% 0.19% +0.05%
3 2025-11-21 0.15%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-20330

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 4.0 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2024-20330

Affected software / configurations for CVE-2024-20330

Vendor Product Version Raw CPE
cisco firepower_threat_defense 7.0.0.0 cpe:2.3:a:cisco:firepower_threat_defense:7.0.0.0:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.0.1 cpe:2.3:a:cisco:firepower_threat_defense:7.0.0.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.1 cpe:2.3:a:cisco:firepower_threat_defense:7.0.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.1.1 cpe:2.3:a:cisco:firepower_threat_defense:7.0.1.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.2 cpe:2.3:a:cisco:firepower_threat_defense:7.0.2:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.2.1 cpe:2.3:a:cisco:firepower_threat_defense:7.0.2.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.3 cpe:2.3:a:cisco:firepower_threat_defense:7.0.3:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.4 cpe:2.3:a:cisco:firepower_threat_defense:7.0.4:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.5 cpe:2.3:a:cisco:firepower_threat_defense:7.0.5:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.6 cpe:2.3:a:cisco:firepower_threat_defense:7.0.6:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.6.1 cpe:2.3:a:cisco:firepower_threat_defense:7.0.6.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.6.2 cpe:2.3:a:cisco:firepower_threat_defense:7.0.6.2:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.0.6.3 cpe:2.3:a:cisco:firepower_threat_defense:7.0.6.3:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.1.0 cpe:2.3:a:cisco:firepower_threat_defense:7.1.0:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.1.0.1 cpe:2.3:a:cisco:firepower_threat_defense:7.1.0.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.1.0.3 cpe:2.3:a:cisco:firepower_threat_defense:7.1.0.3:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.0 cpe:2.3:a:cisco:firepower_threat_defense:7.2.0:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.0.1 cpe:2.3:a:cisco:firepower_threat_defense:7.2.0.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.1 cpe:2.3:a:cisco:firepower_threat_defense:7.2.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.2 cpe:2.3:a:cisco:firepower_threat_defense:7.2.2:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.3 cpe:2.3:a:cisco:firepower_threat_defense:7.2.3:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.4 cpe:2.3:a:cisco:firepower_threat_defense:7.2.4:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.4.1 cpe:2.3:a:cisco:firepower_threat_defense:7.2.4.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.5 cpe:2.3:a:cisco:firepower_threat_defense:7.2.5:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.5.1 cpe:2.3:a:cisco:firepower_threat_defense:7.2.5.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.5.2 cpe:2.3:a:cisco:firepower_threat_defense:7.2.5.2:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.6 cpe:2.3:a:cisco:firepower_threat_defense:7.2.6:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.7 cpe:2.3:a:cisco:firepower_threat_defense:7.2.7:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.8 cpe:2.3:a:cisco:firepower_threat_defense:7.2.8:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.2.8.1 cpe:2.3:a:cisco:firepower_threat_defense:7.2.8.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.3.0 cpe:2.3:a:cisco:firepower_threat_defense:7.3.0:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.3.1 cpe:2.3:a:cisco:firepower_threat_defense:7.3.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.3.1.1 cpe:2.3:a:cisco:firepower_threat_defense:7.3.1.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.3.1.2 cpe:2.3:a:cisco:firepower_threat_defense:7.3.1.2:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.4.1 cpe:2.3:a:cisco:firepower_threat_defense:7.4.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.4.1.1 cpe:2.3:a:cisco:firepower_threat_defense:7.4.1.1:*:*:*:*:*:*:*
cisco firepower_threat_defense 7.4.2 cpe:2.3:a:cisco:firepower_threat_defense:7.4.2:*:*:*:*:*:*:*

References for CVE-2024-20330

cvelogic Threat Intelligence