CVE-2018-0173
Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run IOS and IOS XE Software, fix it now.
CISA required action: Apply updates per vendor instructions.
US federal civilian agencies must remediate by Mar 17, 2022.
Patch status
No official fix confirmed yet
Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.
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.
Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.
Affected products
| Product | Vendor | Affected versions | Source |
|---|---|---|---|
| Cisco networking & security | Cisco | denali-16.3.4; <= 15.2\(6\)e0a; <= 15.2\(4a\)ea5 | NVD |
| IOS | Cisco | denali-16.3.4; <= 15.2\(6\)e0a; <= 15.2\(4a\)ea5 | NVD |
| IOS and IOS XE Software | Cisco | — | KEV |
Sources: NVD = NIST National Vulnerability Database; KEV = CISA Known Exploited Vulnerabilities catalog.
Intelligence timeline
Developments from the last 30 days, newest first.
- CVSS scoredUpdateKEV
CVE-2018-0173 scored CVSS 8.6: Cisco IOS and IOS XE Software, Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
CISA lists this as exploited in the wild. Unpatched IOS and IOS XE Software systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
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Coverage
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