---
id: CVE-2025-66737
title: Yealink T21P_E2 Phone 52.84.0.15 is vulnerable to Directory Traversal
summary: >-
  Yealink T21P_E2 Phone 52.84.0.15 is vulnerable to Directory Traversal. A
  remote normal privileged attacker can read arbitrary files via a crafted
  request result read function of the diagnostic component.
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-23
vendor: yealink
product: sip-t21(p)e2_firmware
affected:
  - sip-t21(p)e2_firmware = 52.84.0.15
published: '2025-12-26'
updated: '2026-10-05'
sourceUpdated: '2026-10-05T18:10:00.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-66737'
references:
  - url: >-
      https://drive.google.com/file/d/1MpxnCL4koKupqWWDmY3ljlybjIPD8ieD/view?usp=sharing
    label: cve@mitre.org
tags:
  - nvd
epss: 0.00661
epssPercentile: 0.49897
ingestedAt: '2026-10-05T18:29:11.161Z'
---

## Overview

Yealink T21P_E2 Phone 52.84.0.15 is vulnerable to Directory Traversal. A remote normal privileged attacker can read arbitrary files via a crafted request result read function of the diagnostic component.

## Affected

- `sip-t21(p)e2_firmware = 52.84.0.15`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.