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Cisco · IOS XR

CVE-2020-3118

Cisco IOS XR Software Discovery Protocol Format String Vulnerability

CISA KEV record

CISA date added
2021-11-03
CISA due date
2022-05-03
Known ransomware use
Unknown

NVD risk context

8.8 HIGH

CVSS is a technical severity score. CISA’s KEV status remains the evidence that this vulnerability is known to be exploited.

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Attack vector
Adjacent
An attacker must be on the same local or adjacent network.
Attack complexity
Low
Exploitation does not require unusual conditions beyond normal attacker control.
Privileges required
None
The attacker does not need an existing account or privileges.
User interaction
None
No action by another user is required.

Description

Cisco IOS XR improperly validates string input from certain fields in Cisco Discovery Protocol messages. Exploitation could allow an unauthenticated, adjacent attacker to execute code with administrative privileges or cause a reload on an affected device.

Required action

Apply updates per vendor instructions.

NVD reference index

Vendor and remediation references

NVD has tagged these sources as vendor advisories, patches, mitigations, or release notes.

Other NVD references (2)

MITRE CWE context

CWE classification

CWE-134 Use of Externally-Controlled Format String

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

View official MITRE CWE details ↗

NVD record timing

NVD record timeline

These dates describe NVD’s record, not CISA’s KEV addition or remediation due date.

NVD published
Feb 05, 2020, 06:15 PM UTC
When NVD first published this CVE record.
NVD last updated
Jun 17, 2026, 03:17 AM UTC
When NVD last changed its analysis or record data.
Advanced: view the technical CVSS vector

This standardized code is intended for security tools and technical analysts. The plain-language risk summary above explains its main points.

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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CISA notes

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