Security readout for executives and security teams
Plain-English summary
CVE-2018-0174 can make affected Cisco IOS and IOS XE devices reload after receiving malformed DHCPv4 option 82 information. The business impact is network outage, not data theft. Because CISA KEV lists it as known exploited, organizations should treat exposed or critical routing and switching infrastructure as urgent.
Executive priority
Prioritize remediation for critical Cisco network devices because the consequence is outage and CISA lists the CVE as known exploited. This should be handled as a high-priority availability risk, especially for branch, industrial, or core network paths.
Technical view
The flaw is incomplete input validation in Cisco IOS and IOS XE DHCP option 82 encapsulation handling. An unauthenticated remote attacker can trigger a device reload through crafted DHCPv4 traffic received from DHCP relay agents. The CVSS 3.1 score is 8.6, with high availability impact and no confidentiality or integrity impact stated.
Likely exposure
Likely exposure is Cisco IOS or IOS XE infrastructure using DHCPv4 option 82 or receiving option 82 information from DHCP relay agents. Risk is highest where untrusted DHCP-related traffic can reach affected devices or where a reload affects core network availability.
Exploitation context
Active exploitation is supported by the CISA Known Exploited Vulnerabilities listing. The provided sources describe unauthenticated remote denial of service through crafted DHCPv4 packets, but do not provide operational exploit details or evidence of data compromise.
Researcher notes
Evidence supports remote unauthenticated DoS against affected Cisco IOS and IOS XE handling DHCPv4 option 82 from relay agents. The source bundle identifies Cisco Bug ID CSCuh91645 and CWE-20. The bundle does not include full fixed-version detail, so rely on Cisco’s advisory for release mapping.
Mitigation direction
- Review Cisco advisory cisco-sa-20180328-dhcpr3 for affected and fixed releases.
- Upgrade affected Cisco IOS and IOS XE software according to Cisco guidance.
- Limit DHCP relay and DHCPv4 traffic paths to trusted network segments.
- Prioritize devices whose reload would disrupt critical business or operational networks.
- Check CISA KEV due dates and internal remediation SLAs for tracked assets.
Validation and detection
- Inventory Cisco IOS and IOS XE devices handling DHCPv4 option 82 information.
- Compare installed software versions with Cisco advisory affected-version guidance.
- Confirm whether DHCP relay agents can send option 82 data to each device.
- Review device logs for unexpected reloads around DHCP processing activity.
- Verify compensating network controls restrict untrusted DHCPv4 traffic paths.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2018-0174 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04CVE reference · x_refsource_MISC
- https://www.tenable.com/security/research/tra-2018-06CVE reference · x_refsource_MISC
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr3CVE reference · x_refsource_CONFIRM
- https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05CVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-0174CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.