How severe is CVE-2020-3308?

CVE-2020-3308 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2020-3308 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3308?

CVE-2020-3308 primarily affects Cisco Firepower Threat Defense. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3308?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-3308 published?

CVE-2020-3308 was published on 2020-05-06 and last updated on 2026-06-17.

CVE-2020-3308

CVE-2020-3308 is a medium-severity vulnerability in Cisco Firepower Threat Defense with a CVSS 3.x base score of 4.9. 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-347.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
CVSS v2: 4.0
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Cisco Firepower Threat Defense
Published: 2020-05-06
Last modified: 2026-06-17

Description

A vulnerability in the Image Signature Verification feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrator-level credentials to install a malicious software patch on an affected device. The vulnerability is due to improper verification of digital signatures for patch images. An attacker could exploit this vulnerability by crafting an unsigned software patch to bypass signature checks and loading it on an affected device. A successful exploit could allow the attacker to boot a malicious software patch image.

Frequently asked questions

What is CVE-2020-3308?: A vulnerability in the Image Signature Verification feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrator-level credentials to install a malicious software patch on an affected device. The vulnerability is due to improper verification of digital signatures for patch images. An attacker could exploit this vulnerability by crafting an unsigned software patch to bypass signature checks and loading it on an affected device. A successful exploit could allow the attacker to boot a malicious software patch image.
How severe is CVE-2020-3308?: CVE-2020-3308 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2020-3308 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3308?: CVE-2020-3308 primarily affects Cisco Firepower Threat Defense. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3308?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3308 published?: CVE-2020-3308 was published on 2020-05-06 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sigbypass-FcvPPCeP

Affected products (3)

cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:secure_firewall_management_center:6.2.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:secure_firewall_management_center:6.2.3:*:*:*:*:*:*:*

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