CVE-2018-0173 on CISA KEV

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 denia

01What CISA says about this 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…

02Required action — verbatim from CISA

Apply updates per vendor instructions.

03Notes & references

• tools.cisco.com — https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-2…
• www.securityfocus.com — http://www.securityfocus.com/bid/103545
• ics-cert.us-cert.gov — https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04
• www.tenable.com — https://www.tenable.com/security/research/tra-2018-06
• www.securitytracker.com — http://www.securitytracker.com/id/1040591
• ics-cert.us-cert.gov — https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05

04SARA's analyst layer — why this matters

This vulnerability is currently on the CISA KEV list, which CISA only adds CVEs to when there is reliable evidence of active exploitation in the wild. For federal civilian agencies, BOD 22-01 requires remediation by the due date above. For everyone else, KEV is the strongest "patch immediately" signal you can get from public threat intel.

05Affected products (summary)

Vendor	Product	Versions
n	a / Cisco IOS and IOS XE	Cisco IOS and IOS XE

06Detection

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