How severe is CVE-2020-3253?

CVE-2020-3253 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-2020-3253 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3253?

CVE-2020-3253 affects Cisco Firepower Threat Defense. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-3253?

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

When was CVE-2020-3253 published?

CVE-2020-3253 was published on 2020-05-06 and last updated on 2026-06-17.

CVE-2020-3253

CVE-2020-3253 is a medium-severity vulnerability in Cisco Firepower Threat Defense 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-284.

Key facts

Severity: Medium (CVSS 3.x base score 6.7)
CVSS v2: 7.2
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Cisco Firepower Threat Defense
Published: 2020-05-06
Last modified: 2026-06-17

Description

A vulnerability in the support tunnel feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to access the shell of an affected device even though expert mode is disabled. The vulnerability is due to improper configuration of the support tunnel feature. An attacker could exploit this vulnerability by enabling the support tunnel, setting a key, and deriving the tunnel password. A successful exploit could allow the attacker to run any system command with root access on an affected device.

Frequently asked questions

What is CVE-2020-3253?: A vulnerability in the support tunnel feature of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to access the shell of an affected device even though expert mode is disabled. The vulnerability is due to improper configuration of the support tunnel feature. An attacker could exploit this vulnerability by enabling the support tunnel, setting a key, and deriving the tunnel password. A successful exploit could allow the attacker to run any system command with root access on an affected device.
How severe is CVE-2020-3253?: CVE-2020-3253 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-2020-3253 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3253?: CVE-2020-3253 affects Cisco Firepower Threat Defense. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-3253?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3253 published?: CVE-2020-3253 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-shell-9rhJF68K

Affected products (1)

cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:*

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