CVE-2020-3253
Cisco Firepower Threat Defense Software Shell Access Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Cisco Firepower Threat Defense Software Shell Access Vulnerability
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.
- Record
CVE-2020-3253- CVSS 3.0
- 6.7 Medium
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
EUVDEUVD-2020-24524
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.
- Record
EUVD-2020-24524- CVSS 3.0
- 6.7 Medium
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-v33g-rjxr-6hm4
A vulnerability in the support tunnel feature of Cisco Firepower Threat Defense (FTD) Software...
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.
- Record
GHSA-v33g-rjxr-6hm4- CVSS 3.1
- 6.7 Medium
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2020-3253- CVSS 3.1
- 6.7 Medium
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 6.7 Medium
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.2 High
AV:L/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-284
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-3253 is a medium vulnerability (CVSS 6.7) in Cisco Firepower Threat Defense Software, published May 6, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 23rd percentile. No source names a fixed version.