CVE-2021-34762 [High] | Path Traversal in Firepower Management Cent…

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.19%	1.91%	+1.71%
2	2025-11-21	0.10%	0.19%	+0.09%
3	2025-11-18	—	0.10%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.19%

1.91%

+1.71%

2025-11-21

0.10%

0.19%

+0.09%

2025-11-18

—

0.10%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
8.1	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.	2.8	5.2	[email protected]
8.1	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.	2.8	5.2	[email protected]
5.5	2.0	MEDIUM	`AV:N/AC:L/Au:S/C:P/I:P/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	8.0	4.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

8.1

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N): Service keeps running; no real outage angle.

2.8

5.2

[email protected]

8.1

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N): Service keeps running; no real outage angle.

2.8

5.2

[email protected]

5.5

2.0

MEDIUM

AV:N/AC:L/Au:S/C:P/I:P/A:N Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:S): A single authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

8.0

4.9

[email protected]

Affected software / configurations for CVE-2021-34762

Vendor	Product	Version	Raw CPE
cisco	firepower_management_center_virtual_appliance	6.2.3	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.2.3:::::::*
cisco	firepower_management_center_virtual_appliance	6.4.0	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.4.0:::::::*
cisco	firepower_management_center_virtual_appliance	6.5.0	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.5.0:::::::*
cisco	firepower_management_center_virtual_appliance	6.6.1	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.1:::::::*
cisco	firepower_management_center_virtual_appliance	6.6.2	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.2:::::::*
cisco	firepower_management_center_virtual_appliance	6.6.3	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.3:::::::*
cisco	firepower_management_center_virtual_appliance	6.6.4	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.6.4:::::::*
cisco	firepower_management_center_virtual_appliance	6.7.0	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:6.7.0:::::::*
cisco	firepower_management_center_virtual_appliance	7.0.0	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:7.0.0:::::::*
cisco	firepower_management_center_virtual_appliance	7.1.0	cpe:2.3:a:cisco:firepower_management_center_virtual_appliance:7.1.0:::::::*
cisco	firepower_threat_defense	< 6.4.0.13	cpe:2.3:a:cisco:firepower_threat_defense::::::::
cisco	firepower_threat_defense	>= 6.5.0, < 6.6.5	cpe:2.3:a:cisco:firepower_threat_defense::::::::
cisco	firepower_threat_defense	>= 6.7.0, < 6.7.0.3	cpe:2.3:a:cisco:firepower_threat_defense::::::::
cisco	firepower_threat_defense	>= 7.0.0, < 7.0.1	cpe:2.3:a:cisco:firepower_threat_defense::::::::
cisco	sourcefire_defense_center	6.2.3	cpe:2.3:a:cisco:sourcefire_defense_center:6.2.3:::::::*
cisco	sourcefire_defense_center	6.4.0	cpe:2.3:a:cisco:sourcefire_defense_center:6.4.0:::::::*
cisco	sourcefire_defense_center	6.5.0	cpe:2.3:a:cisco:sourcefire_defense_center:6.5.0:::::::*
cisco	sourcefire_defense_center	6.6.1	cpe:2.3:a:cisco:sourcefire_defense_center:6.6.1:::::::*
cisco	sourcefire_defense_center	6.6.2	cpe:2.3:a:cisco:sourcefire_defense_center:6.6.2:::::::*
cisco	sourcefire_defense_center	6.6.3	cpe:2.3:a:cisco:sourcefire_defense_center:6.6.3:::::::*
cisco	sourcefire_defense_center	6.6.4	cpe:2.3:a:cisco:sourcefire_defense_center:6.6.4:::::::*
cisco	sourcefire_defense_center	7.0.0	cpe:2.3:a:cisco:sourcefire_defense_center:7.0.0:::::::*

References for CVE-2021-34762

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

URL

CVE-2021-34762 | Cisco Firepower Management Center Software Authenticated Directory Traversal Vulnerability

Exploit prediction scoring system (EPSS) score for CVE-2021-34762

Common vulnerability scoring system (CVSS) metrics for CVE-2021-34762

Weakness enumeration for CVE-2021-34762

Affected software / configurations for CVE-2021-34762

References for CVE-2021-34762