CubePath
Sign Up

CVE-2018-0173

Improper Input Validation

CVSS 3.1 High 8.6Known exploited (CISA KEV)

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

Description

A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4) packets could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a Relay Reply denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of encapsulated option 82 information that it receives in DHCPOFFER messages from DHCPv4 servers. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device, which the device would then forward to a DHCPv4 server. When the affected software processes the option 82 information that is encapsulated in the response from the server, an error could occur. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvg62754.

Official description from the CVE record, published by cisco. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org

Key data

CVSS 3.1 High 8.6

Score published by CISA-ADP in the CVE record.

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

  • Attack vector: Network

    The vulnerable component can be reached over a network, possibly from the Internet.

  • Attack complexity: Low

    No special conditions are needed. The attack can be repeated at will.

  • Privileges required: None

    No account or privileges are needed.

  • User interaction: None

    No action from any user is needed.

  • Scope: Changed

    The impact can reach other components beyond the vulnerable one.

  • Confidentiality impact: None

    No effect on the secrecy of data.

  • Integrity impact: None

    No effect on the trustworthiness of data.

  • Availability impact: High

    Serious or total effect on availability.

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.

EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.
Score
0.07608 (7.6% probability)
Percentile
94.6%
Scores of
Nov 10, 2026
Model
v2026.06.15

CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.
Name in the catalog
Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
Added to the catalog
Mar 3, 2022
Federal due date
Mar 17, 2022

CISA assessment as of Nov 8, 2024

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.
Exploitation
Recorded by CISA as active
Automatable
no
Technical impact
total

Weakness (CWE)

CWE catalog version 5.0.
CWE names: Copyright © 2006-2026, The MITRE Corporation. See /security/cve/legal for the CWE license.
  • CWE-20Improper Input Validation

Affected products

Products listed in the CVE record, as the CNA published them.

  • Cisco IOS and IOS XE

    • affected: Cisco IOS and IOS XE

References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

Timeline

  1. ID reserved
  2. Record published
  3. Added to CISA KEV
  4. Record last updated

Look up another CVE

About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.
Cloud VPSDDoS protection

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:32 UTC. Sources and licenses