How severe is CVE-2020-3179?

CVE-2020-3179 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-3179 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3179?

CVE-2020-3179 primarily affects Cisco Firepower Threat Defense. In total, 25 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3179?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-3179 published?

CVE-2020-3179 was published on 2020-05-06 and last updated on 2026-06-17.

CVE-2020-3179

CVE-2020-3179 is a high-severity vulnerability in Cisco Firepower Threat Defense with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-415.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-415
Affected product: Cisco Firepower Threat Defense
Published: 2020-05-06
Last modified: 2026-06-17

Description

A vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a memory handling error when GRE over IPv6 traffic is processed. An attacker could exploit this vulnerability by sending crafted GRE over IPv6 packets with either IPv4 or IPv6 payload through an affected device. A successful exploit could allow the attacker to cause the device to crash, resulting in a DoS condition.

Frequently asked questions

What is CVE-2020-3179?: A vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a memory handling error when GRE over IPv6 traffic is processed. An attacker could exploit this vulnerability by sending crafted GRE over IPv6 packets with either IPv4 or IPv6 payload through an affected device. A successful exploit could allow the attacker to cause the device to crash, resulting in a DoS condition.
How severe is CVE-2020-3179?: CVE-2020-3179 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-3179 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3179?: CVE-2020-3179 primarily affects Cisco Firepower Threat Defense. In total, 25 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3179?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-3179 published?: CVE-2020-3179 was published on 2020-05-06 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-2-sS2h7aWe

Affected products (25)

cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5505_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5505_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5510_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5510_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5512-x_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5512-x_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5515-x_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5515-x_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5520_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5520_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5525-x_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5525-x_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5540_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5540_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5545-x_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5545-x_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5550_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5550_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5555-x_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5555-x_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5580_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5580_firmware:101.5\(1.26\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5585-x_firmware:9.9\(2\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:asa_5585-x_firmware:101.5\(1.26\):*:*:*:*:*:*:*

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