# CVE-2018-0172: Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

Source: https://junglewise.ai/threats/cve-2018-0172-cisco-ios-and-ios-xe-software-improper-input-validation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-03-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2018-0172 · Severity: critical · CVSS 8.6 · Exploited in the wild · Published 2022-03-03

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS and IOS XE Software allows an unauthenticated, remote attacker to cause a heap overflow. This occurs due to incomplete input validation of option 82 information in DHCPv4 packets, potentially leading to a device reload and denial-of-service (DoS) condition.

Technologies: [Cisco IOS](https://junglewise.ai/threats/technologies/ios), [Cisco IOS XE](https://junglewise.ai/threats/technologies/ios-xe), [Cisco IOS XE Software](https://junglewise.ai/threats/technologies/ios-xe-software), [Cisco IOS XR](https://junglewise.ai/threats/technologies/ios-xr). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2018-0172 exploited in the wild?** Yes. CVE-2018-0172 is known to be exploited in the wild, first recorded on 3 March 2022. Treat it as urgent.

**How severe is CVE-2018-0172?** Critical severity, with a CVSS score of 8.6, published 3 March 2022.

**Which products and versions are affected?** Cisco IOS Software; Cisco IOS XE Software; Rockwell Automation Allen-Bradley ArmorStratix 5700; Rockwell Automation Allen-Bradley Stratix 5400; and 4 more.

**Is there a fix for CVE-2018-0172?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2018-0172 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2018-0172?** Check whether you run Cisco IOS, Cisco IOS XE, Cisco IOS XE Software or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Cisco IOS Software
- Cisco IOS XE Software
- Rockwell Automation Allen-Bradley ArmorStratix 5700
- Rockwell Automation Allen-Bradley Stratix 5400
- Rockwell Automation Allen-Bradley Stratix 5410
- Rockwell Automation Allen-Bradley Stratix 5700
- Rockwell Automation Allen-Bradley Stratix 8000
- Rockwell Automation Allen-Bradley Stratix 8300

## Timeline

- 2018-03-28: advisory: Cisco published the initial security advisory.
- 2022-03-03: kev added: Added to CISA's Known Exploited Vulnerabilities Catalog.
- 2022-03-03: disclosed: Publication date listed in the advisory.
- 2022-03-03: exploited: Confirmed as exploited in the wild per CISA KEV entry.

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- [Cisco Snort 3 Detection Engine denial of service in GTP codec](https://junglewise.ai/threats/cve-2026-76445-multiple-cisco-products-are-affected-by-a-vulnerability-in-the)
- [Cisco Snort 3 incorrect calculation vulnerability](https://junglewise.ai/threats/cve-2026-20236-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and)
- [Cisco Snort 3 GRE detection engine denial of service](https://junglewise.ai/threats/cve-2026-20179-multiple-cisco-products-are-affected-by-a-vulnerability-in-the)
- [Cisco Snort 3 out-of-bounds write](https://junglewise.ai/threats/cve-2026-20043-as-part-of-cisco-s-ongoing-commitment-to-proactive-security-and)