CVE-2020-3120 json
Cisco FXOS, IOS XR, and NX-OS Software Cisco Discovery Protocol Denial of Service Vulnerability
published 2020-02-05 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-24391
- cvss
- 7.4
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.6%
- EPSS 1.6% chance of exploitation in 30 days, percentile 76%
- public exploits
- 0
- none known
Summary
A vulnerability in the Cisco Discovery Protocol implementation for Cisco FXOS Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a missing check when the affected software processes Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to exhaust system memory, causing the device to reload. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).
Patch / fix
- Cisco Cisco IOS XR Software 2.3.1.173
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 23 mo ago
Exploit prediction
1.64% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 7.4 | CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 6.1 | AV:A/AC:L/Au:N/C:N/I:N/A:C |
Affected products
- Cisco Cisco IOS XR Software
Classification
- Weakness
-
- CWE-190 Integer Overflow or Wraparound
- Technology feeds
References
-
tools.cisco.com
/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200205-fxnxos-iosxr-cdp-dos
vendor-advisory
-
packetstormsecurity.com
/files/156203/Cisco-Discovery-Protocol-CDP-Remote-Device-Takeover.html
third-party-advisory, vdb-entry
Sources
- CVE List CVE-2020-3120
- NVD CVE-2020-3120
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