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CISA Known Exploited Vulnerabilities

Cisco IOS XR Software Discovery Protocol Format String Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV
2021-11-03
Remediation due
2022-05-03

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2020-3118

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).

Severity

CVSS 3.0 · CNA8.8 HIGH
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC · CISA-ADP
Exploitationactive
Automatableno
Technical impacttotal

Exploitation Context

as of October 14, 2026
All KEV statistics→
  • CISA added CVE-2020-3118 to the KEV catalog 637 days after its CVE record was published.
  • It is one of 100 Cisco entries in the CISA KEV catalog, and one of 11 added in 2021.
  • Its current EPSS score (11.7%) is higher than that of 28% of CISA KEV entries.

Affected Products

ProductAffected versions
Cisco
Cisco IOS XR Software
unspecified to <6.6.3

References

2 Links

Record Details

Published
2020-02-05
Last updated
2025-10-21
Assigner (CNA)
cisco
Credited to
-

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.