CVE-2022-20625 [Medium] | Denial of Service in Firepower Extensible Oper…

A vulnerability in the Cisco Discovery Protocol service of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause the service to restart, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of Cisco Discovery Protocol messages that are processed by the Cisco Discovery Protocol service. An attacker could exploit this vulnerability by sending a series of malicious Cisco Discovery Protocol messages to an affected device. A successful exploit could allow the attacker to cause the Cisco Discovery Protocol service to fail and restart. In rare conditions, repeated failures of the process could occur, which could cause the entire device to restart.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-24	3.32%	3.40%	+0.08%
2	2026-06-15	1.67%	3.32%	+1.65%
3	2026-02-11	—	1.67%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-24

3.32%

3.40%

+0.08%

2026-06-15

1.67%

3.32%

+1.65%

2026-02-11

—

1.67%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.3	3.1	MEDIUM	`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. 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:N) No account or special rights needed—anonymous or random user is enough. 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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	2.8	1.4	[email protected]
4.3	3.1	MEDIUM	`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. 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:N) No account or special rights needed—anonymous or random user is enough. 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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	2.8	1.4	[email protected]
6.1	2.0	MEDIUM	`AV:A/AC:L/Au:N/C:N/I:N/A:C` Click to expand Access vector (AV:A) Requires access to an adjacent network segment. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:C) Complete availability impact.	6.5	6.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.3

3.1

MEDIUM

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

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:N): No account or special rights needed—anonymous or random user is enough.
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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

2.8

1.4

[email protected]

4.3

3.1

MEDIUM

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

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:N): No account or special rights needed—anonymous or random user is enough.
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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

2.8

1.4

[email protected]

6.1

2.0

MEDIUM

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

Access vector (AV:A): Requires access to an adjacent network segment.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:C): Complete availability impact.

6.5

6.9

[email protected]

Affected software / configurations for CVE-2022-20625

Vendor	Product	Version	Raw CPE
cisco	firepower_extensible_operating_system	< 2.3.1.219	cpe:2.3:o:cisco:firepower_extensible_operating_system::::::::
cisco	firepower_extensible_operating_system	>= 2.4, < 2.9.1.158	cpe:2.3:o:cisco:firepower_extensible_operating_system::::::::
cisco	firepower_extensible_operating_system	>= 2.10, < 2.10.1.179	cpe:2.3:o:cisco:firepower_extensible_operating_system::::::::
cisco	nx-os	8.2\(7.34\)	cpe:2.3:o:cisco:nx-os:8.2\(7.34\):::::::*
cisco	nx-os	5.2\(1\)sv5\(1.3b\)	cpe:2.3:o:cisco:nx-os:5.2\(1\)sv5\(1.3b\):::::::*
cisco	nx-os	9.3\(8.15\)	cpe:2.3:o:cisco:nx-os:9.3\(8.15\):::::::*
cisco	nx-os	4.0\(1a\)a	cpe:2.3:o:cisco:nx-os:4.0\(1a\)a:::::::*
cisco	nx-os	4.1\(3f\)c	cpe:2.3:o:cisco:nx-os:4.1\(3f\)c:::::::*

References for CVE-2022-20625

URL	Tags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cdp-dos-G8DPLWYG	Vendor Advisory

URL

CVE-2022-20625 | Cisco FXOS and NX-OS Software Cisco Discovery Protocol Service Denial of Service Vulnerability

Exploit prediction scoring system (EPSS) score for CVE-2022-20625

Common vulnerability scoring system (CVSS) metrics for CVE-2022-20625

Weakness enumeration for CVE-2022-20625

Affected software / configurations for CVE-2022-20625

References for CVE-2022-20625