CVE-2018-0173

highpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.076 · 95 %ileDEEURUUS
grimoire priorityP0 · Act now
Exploitable?
Yes · in the wild
CISA KEV
Likely / severe?
7.61% (95th) EPSS
CVSS 7.8 · high
Is it mine?
800 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

added 2022-03-03remediate by 2022-03-17

required action Apply updates per vendor instructions.

EPSS · scored 2026-10-27

Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

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.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

8.6
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.07.8highAV:N/AC:L/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 10 · impact 6.9
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 4
v3.08.6highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US
v3.08.6highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · CISA US
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondaryexploitability 3.9 · impact 4
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:Hsecondary · CVSS-BT (t0sche)
v3.18.6highAV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20USCWE-20US
05

affected products (800)

Products and version ranges known to be affected.

showing 20 of 800
06

advisories (3)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2025-1871Cisco IOS: Mehrere SchwachstellenDeutsch2018-03-28csaf · cert_bundDE

    Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Cisco IOS und Cisco IOS XE ausnutzen, um Daten zu manipulieren, vertrauliche Daten einzusehen, einen Denial of Service Angriff durchzuführen, seine Privilegien zu erweitern, Cross-Site Scripting Angriffe durchzuführen, Sicherheitsmechanismen zu umgehen oder beliebigen Code mit administrativen Privilegien zur Ausführung zu bringen.

  • cisco-sa-20180328-dhcpr2Cisco IOS and IOS XE Software DHCP Version 4 Relay Reply Denial of Service Vulnerability2018-03-28csaf · cisco_csafUS

    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 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 has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr2 ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr2"] This advisory is part of the March 28, 2018, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 20 Cisco Security Advisories that describe 22 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: March 2018 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-66682"].

  • ICSA-18-107-04Rockwell Automation Stratix and ArmorStratix Switches2018-04-17icsa · cisa_csaf_otUS

    Successful exploitation of these vulnerabilities could result in loss of availability, confidentiality, and/or integrity caused by memory exhaustion, module restart, information corruption, and/or information exposure.

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundcisa_csaf_otcisco_csafNVDCVE.orgMITRE
published 2018-03-28modified 2026-06-17
10

references (19)

External citations — patches, advisories, analysis.

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