CVEvulnerability

CVE-2020-3118

8.8 HIGH Known exploited Published 2020-02-05 Modified 2026-06-17 Official page ↗

CISA Known Exploited Vulnerability

Cisco IOS XR Software Discovery Protocol Format String Vulnerability — Cisco IOS XR

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.

Added to KEV: 2021-11-03
Remediation due: 2022-05-03
Ransomware use: Unknown
Required action: Apply updates per vendor instructions.
Notes: https://nvd.nist.gov/vuln/detail/CVE-2020-3118

Status: Analyzed
Published: 2020-02-05
Last modified: 2026-06-17
Assigner: [email protected]
CVSS 3.1 ([email protected]): 8.8 HIGH — CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.0 ([email protected]): 8.8 HIGH — CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected]): 8.3 HIGH — AV:A/AC:L/Au:N/C:C/I:C/A:C
Weaknesses: CWE-134, CWE-787

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).

Affected configurations

• cisco ios xr (>= 6.6.0 < 6.6.12) • cisco ios xr (>= 7.0.0 < 7.0.2) • cisco ios xr 6.5.3 • cisco ios xr 5.2.5 • cisco ios xr 6.4.2 • cisco ios xr 6.6.25 • cisco ios xr 7.0.1

Weakness · CWE (2)

CWE-134 Use of Externally-Controlled Format String weakness
CWE-787 Out-of-bounds Write weakness

References