CVE-2018-0173 Cisco IOS and IOS XE Software Improper Input Validation
Remote attackers can cause a denial of service on Cisco IOS devices by sending crafted DHCPv4 packets that trigger a reload due to improper input validation.
- Exploited in the wild
- Since 3 Mar 2022
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2018-0173?
CVE-2018-0173 is a high-severity denial of service vulnerability in Cisco Ios, published on 28 Mar 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-20
Which versions are affected by CVE-2018-0173?
It affects 2 products.
Products include Cisco Ios, Cisco Ios Xe.
How do I fix CVE-2018-0173?
No fix has been published for CVE-2018-0173 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 17 Mar 2022.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2018-0173 being exploited?
Yes. Attackers have exploited CVE-2018-0173 in the wild since at least 3 Mar 2022.
Other vulnerabilities in Cisco Ios
- CVE-2017-12240 Cisco IOS and IOS XE Software DHCP Remote Code Execution
- CVE-2017-3881 Cisco IOS and IOS XE Remote Code Execution
- CVE-2018-0167 Cisco IOS, XR, and XE Software Buffer Overflow
- CVE-2017-6736 Cisco IOS and IOS XE Software SNMP Remote Code Execution
- CVE-2017-6737 Cisco IOS and IOS XE Software SNMP Remote Code Execution
Sources
Also known as GHSA-pp38-rv9h-g7rc.