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ExploitedIn CISA KEV

CVE-2018-0173

Exploitation confirmed. First attested on 2022-03-03 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2018-03-28
  • WeaknessCWE-20

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2018-03-2822:29CVE publishedNVD
  2. 2022-03-03Added to the CISA KEV catalogCISA KEV
  3. 2022-03-03Listed as exploited by GCVEGCVE
  4. 2022-03-03Exploitation first reportedCISA KEV
  5. 2024-11-0817:23SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-0173?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-0173?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Cisco iosversion to verify
BranchAffectedFixed in
—= denali-16.3.4no fix published
15.2≤ 15.2\(6\)e0ano fix published
15.2≤ 15.2\(4a\)ea5no fix published
Cisco ios xeversion to verify
BranchAffectedFixed in
—= denali-16.3.4no fix published
15.2≤ 15.2\(6\)e0ano fix published
15.2≤ 15.2\(4a\)ea5no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As cisco, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Cisco IOS and IOS XE
    Affected
    • = Cisco IOS and IOS XEno fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2018-04-19

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • ICSA-18-107-04 CISA5 known affected

    Rockwell Automation Stratix and ArmorStratix Switches

    Allen-Bradley Stratix 5400 Industrial Ethernet Switches: versions 15.2(6)E0a and earlier; · Allen-Bradley Stratix 8000 Modular Managed Ethernet Switches: versions 15.2(6)E0a and earlier; · Allen-Bradley Stratix 5410 Industrial Distribution Switches: versions 15.2(6)E0a and earlier; · +2 more

Full record on NVD

Fix

  1. CISA’s required action: Apply updates per vendor instructions.due 2022-03-17
  2. Mitigation from the vendor CISA ICSA-18-107-04 · 5 productsRockwell Automation recommends users upgrade to FRN 15.2(6)E1 or later.
  3. Mitigation from the vendor CISA ICSA-18-107-04 · 5 productsRockwell Automation has provided knowledge base article number 1073268 on their website
  4. Mitigation from the vendor CISA ICSA-18-107-04 · 5 productsCisco has released new Snort Rules at https://www.cisco.com/web/software/286271056/117258/sf-rules-2018-03-29-new.htm
  5. Mitigation from the vendor CISA ICSA-18-107-04 · 5 productsCVE-2018-0173 - Snort Rule 46119
  6. Mitigation from the vendor CISA ICSA-18-107-04 · 5 productsHelp minimize network exposure for all control system devices and/or systems, and confirm that they are not accessible from the Internet.
  7. Mitigation from the vendor CISA ICSA-18-107-04 · 5 productsLocate control system networks and devices behind firewalls, and isolate them from the business network.

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2022-03-03
Patch Due Date
2022-03-17
Ransomware Use
Unknown
Required Action
Apply updates per vendor instructions.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Published
2018-03-28
Last Modified
2026-06-17
NVD status
Analyzed
GitHub Advisory
GHSA-pp38-rv9h-g7rc

Frequently asked questions

What is CVE-2018-0173?

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.

Is CVE-2018-0173 actively exploited?

Yes. CVE-2018-0173 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-03-17.

What is the CVSS score for CVE-2018-0173?

CVE-2018-0173 has a CVSS v3 base score of 8.6 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

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