CVE-2025-65821
"ESP32 UART Download Mode Firmware Vulnerability"
Description
As UART download mode is still enabled on the ESP32 chip on which the firmware runs, an adversary can dump the flash from the device and retrieve sensitive information such as details about the current and previous Wi-Fi network from the NVS partition. Additionally, this allows the adversary to reflash the device with their own firmware which may contain malicious modifications.
INFO
Published Date :
Dec. 10, 2025, 9:16 p.m.
Last Modified :
Dec. 11, 2025, 9:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2025-65821
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Disable UART download mode in firmware.
- Secure flash memory access.
- Remove debug interfaces in production.
- Update firmware to prevent future issues.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-65821.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-65821 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-65821
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-65821 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-65821 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Dec. 11, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-1191 -
New CVE Received by [email protected]
Dec. 10, 2025
Action Type Old Value New Value Added Description As UART download mode is still enabled on the ESP32 chip on which the firmware runs, an adversary can dump the flash from the device and retrieve sensitive information such as details about the current and previous Wi-Fi network from the NVS partition. Additionally, this allows the adversary to reflash the device with their own firmware which may contain malicious modifications. Added Reference https://gist.github.com/dead1nfluence/4dffc239b4a460f41a03345fd8e5feb5#file-uart-download-mode-enabled-md Added Reference https://github.com/dead1nfluence/Meatmeet-Pro-Vulnerabilities/blob/main/Device/UART-Download-Mode-Enabled.md