Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-3118

CVE-2020-3118HIGH

Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   A   L   N   N  U  H  H  H    8.8   .1168   95.9   YES

AFFECTED
  Product                Versions       Fixed
  Cisco IOS XR Software  unspecified –  —

TIMELINE
  Dec 12  Reserved by cisco
  Feb 5   Published (CNA: cisco)
  Nov 3   Added to CISA KEV, remediation due 2022-05-03

CWE-134 · CNA: cisco · CVSS v3.0 · 3 references · KEV due May 3, 2022

Description

A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in 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 cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. 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).

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
December 12, 2019	Reserved	Reserved by cisco
February 5, 2020	Published	Published (CNA: cisco)
November 3, 2021	KEV ADDED	Added to CISA KEV, remediation due 2022-05-03

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Cisco	Cisco IOS XR Software	—	unspecified	—

Weaknesses

CWE-134

References (3)

http://packetstormsecurity.com/files/156203/Cisco-Discovery-Protocol-CDP-Remote-Device-Takeover.html [x_refsource_MISC]
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200205-iosxr-cdp-rce [vendor-advisory, x_refsource_CISCO]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3118 [government-resource]

Authoritative record: CVE-2020-3118 at cve.org

Vendors: cisco

Weaknesses: CWE-134

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-3118 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.