CVE-2018-0303

A vulnerability in the Cisco Discovery Protocol component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code as root or cause a denial of service (DoS) condition on the affected device. The vulnerability exists because of insufficiently validated Cisco Discovery Protocol packet headers. An attacker could exploit this vulnerability by sending a crafted Cisco Discovery Protocol packet to a Layer 2 adjacent affected device. A successful exploit could allow the attacker to cause a buffer overflow that could allow the attacker to execute arbitrary code as root or cause a DoS condition on the affected device. This vulnerability affects the following if configured to use Cisco Discovery Protocol: Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 1000V Series Switches, Nexus 1100 Series Cloud Services Platforms, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvc22202, CSCvc22205, CSCvc22208, CSCvc88078, CSCvc88150, CSCvc88159, CSCvc88162, CSCvc88167.

Published: 2018-06-21 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-0303 is rated Moderate Risk (58/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.15%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-0303

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.23% 1.15% +0.92%
2 2026-04-21 0.42% 0.23% -0.18%
3 2025-11-21 0.42%

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-0303

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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: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:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
8.3 2.0 HIGH
AV:A/AC:L/Au:N/C:C/I:C/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:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
6.5 10.0 [email protected]

Weakness enumeration for CVE-2018-0303

Affected software / configurations for CVE-2018-0303

Vendor Product Version Raw CPE
cisco nx-os 7.0\(0\)hsk\(0.357\) cpe:2.3:o:cisco:nx-os:7.0\(0\)hsk\(0.357\):*:*:*:*:*:*:*
cisco nx-os 8.1\(0.2\)s0 cpe:2.3:o:cisco:nx-os:8.1\(0.2\)s0:*:*:*:*:*:*:*
cisco nx-os 8.8\(0.1\) cpe:2.3:o:cisco:nx-os:8.8\(0.1\):*:*:*:*:*:*:*
cisco nx-os 8.0\(1\) cpe:2.3:o:cisco:nx-os:8.0\(1\):*:*:*:*:*:*:*
cisco nx-os 8.8\(3.5\)s0 cpe:2.3:o:cisco:nx-os:8.8\(3.5\)s0:*:*:*:*:*:*:*
cisco nx-os 7.0\(3\)i4\(7\) cpe:2.3:o:cisco:nx-os:7.0\(3\)i4\(7\):*:*:*:*:*:*:*
cisco nx-os 7.0\(3\)i7\(1\) cpe:2.3:o:cisco:nx-os:7.0\(3\)i7\(1\):*:*:*:*:*:*:*
cisco nx-os 3.1\(3a\)a cpe:2.3:o:cisco:nx-os:3.1\(3a\)a:*:*:*:*:*:*:*
cisco firepower_extensible_operating_system >= 1.1, < 1.1.4.179 cpe:2.3:o:cisco:firepower_extensible_operating_system:*:*:*:*:*:*:*:*
cisco firepower_extensible_operating_system >= 2.0, < 2.0.1.153 cpe:2.3:o:cisco:firepower_extensible_operating_system:*:*:*:*:*:*:*:*
cisco firepower_extensible_operating_system >= 2.1.1, < 2.1.1.86 cpe:2.3:o:cisco:firepower_extensible_operating_system:*:*:*:*:*:*:*:*
cisco firepower_extensible_operating_system >= 2.2.1, < 2.2.1.70 cpe:2.3:o:cisco:firepower_extensible_operating_system:*:*:*:*:*:*:*:*
cisco firepower_extensible_operating_system >= 2.2.2, < 2.2.2.17 cpe:2.3:o:cisco:firepower_extensible_operating_system:*:*:*:*:*:*:*:*

References for CVE-2018-0303

cvelogic Threat Intelligence