How severe is CVE-2021-34756?

CVE-2021-34756 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-34756 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34756?

CVE-2021-34756 primarily affects Cisco Firepower Management Center Virtual Appliance. In total, 25 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-34756?

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

When was CVE-2021-34756 published?

CVE-2021-34756 was published on 2021-10-27 and last updated on 2026-06-17.

CVE-2021-34756

CVE-2021-34756 is a medium-severity vulnerability in Cisco Firepower Management Center Virtual Appliance with a CVSS 3.x base score of 6.7. 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-78.

Key facts

Severity: Medium (CVSS 3.x base score 6.7)
CVSS v2: 7.2
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Cisco Firepower Management Center Virtual Appliance
Published: 2021-10-27
Last modified: 2026-06-17

Description

Multiple vulnerabilities in the CLI of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary commands with root privileges. For more information about these vulnerabilities, see the Details section of this advisory.

Frequently asked questions

What is CVE-2021-34756?: Multiple vulnerabilities in the CLI of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary commands with root privileges. For more information about these vulnerabilities, see the Details section of this advisory.
How severe is CVE-2021-34756?: CVE-2021-34756 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-34756 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34756?: CVE-2021-34756 primarily affects Cisco Firepower Management Center Virtual Appliance. In total, 25 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34756?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-34756 published?: CVE-2021-34756 was published on 2021-10-27 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-cmdinject-FmzsLN8

Affected products (25)

cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.1.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.2.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.2.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.3.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.4.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.4.0.11:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.5.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.7.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:7.0.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:7.1.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.1.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.2.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.2.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.3.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.4.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.4.0.11:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.5.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.6.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.6.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.7.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:7.0.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:7.1.0:*:*:*:*:*:*:*

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