How severe is CVE-2021-34762?

CVE-2021-34762 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-34762 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34762?

CVE-2021-34762 primarily affects Cisco Firepower Management Center Virtual Appliance. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-34762?

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-2021-34762 published?

CVE-2021-34762 was published on 2021-10-27 and last updated on 2026-06-17.

CVE-2021-34762

CVE-2021-34762 is a high-severity vulnerability in Cisco Firepower Management Center Virtual Appliance with a CVSS 3.x base score of 8.1. 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-22.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 5.5
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Cisco Firepower Management Center Virtual Appliance
Published: 2021-10-27
Last modified: 2026-06-17

Description

A vulnerability in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an authenticated, remote attacker to perform a directory traversal attack on an affected device. The attacker would require valid device credentials. The vulnerability is due to insufficient input validation of the HTTPS URL by the web-based management interface. An attacker could exploit this vulnerability by sending a crafted HTTPS request that contains directory traversal character sequences to an affected device. A successful exploit could allow the attacker to read or write arbitrary files on the device.

Frequently asked questions

What is CVE-2021-34762?: A vulnerability in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an authenticated, remote attacker to perform a directory traversal attack on an affected device. The attacker would require valid device credentials. The vulnerability is due to insufficient input validation of the HTTPS URL by the web-based management interface. An attacker could exploit this vulnerability by sending a crafted HTTPS request that contains directory traversal character sequences to an affected device. A successful exploit could allow the attacker to read or write arbitrary files on the device.
How severe is CVE-2021-34762?: CVE-2021-34762 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-34762 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34762?: CVE-2021-34762 primarily affects Cisco Firepower Management Center Virtual Appliance. In total, 19 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34762?: 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-2021-34762 published?: CVE-2021-34762 was published on 2021-10-27 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-dir-traversal-95UyW5tk

Affected products (19)

cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.2.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.4.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.5.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.4:*:*:*:*:*:*:*
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:6.2.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.4.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.5.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.6.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.6.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.6.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:6.6.4:*:*:*:*:*:*:*
cpe:2.3:a:cisco:sourcefire_defense_center:7.0.0:*:*:*:*:*:*:*

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