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Vulnerability record · public intelligence
CVE-2023-20244
HIGH

CVE-2023-20244

Published Nov 1, 2023 · Updated Nov 3, 2026

Severity · CVSSHIGH · Not scored
Known exploitationNot listed
EPSS / likelihood1.04%
QFinch risk scoreNot available

Original summary

Normalized public record · Updated Nov 3, 2026

A vulnerability in the internal packet processing of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Firewalls could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain packets when they are sent to the inspection engine. An attacker could exploit this vulnerability by sending a series of crafted packets to an affected device. A successful exploit could allow the attacker to deplete all 9,472 byte blocks on the device, resulting in traffic loss acros

Publisher and source text is retained separately from QFinch interpretation.

QFinch assessment

A vulnerability in the internal packet processing of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Firewalls could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain packets when they are sent to the inspection engine. An attacker could exploit this vulnerability by sending a series of crafted packets to an affected device. A successful exploit could allow the attacker to deplete all 9,472 byte blocks on the device, resulting in traffic loss across the device or an unexpected reload of the device. If the device does not reload on its own, a manual reload of the device would be required to recover from this state.

Evidence: public source records

Affected products

Affected scope reported by the available public evidence
Affected package, product or rangeFix status
Consult the referenced vendor advisory for affected versions.Consult source advisory

Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.

Remediation

Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.

  1. Confirm the affected product and reachable code path exist in your environment.
  2. Apply the vendor-supported patch or mitigation from the primary advisory.
  3. Rescan the exact deployed revision and retain verification evidence.
Review primary references

Evidence coverage

FIRST-EPSSCVE-LIST-V5
SSVC priority
MEDIUM
Confidence
Not available
Aliases
None reported

Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.

Sources and record history

  1. cisco-sa-ftd-intrusion-dos-DfT7wyGC ↗

Record history

Published Nov 1, 2023 · Last refreshed Nov 3, 2026