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Fencer Vulns
high 7.5

CVE-2025-65821 json

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 re…

published 2025-12-10 10 mo ago modified 2026-11-04 4 d ago also EUVD-2025-202625

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

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.

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
10 mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Classification

Weakness
  • CWE-1191 On-Chip Debug and Test Interface With Improper Access Control

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.