CVE-2025-53540Public exploitNetwork attack vector

Remote code execution via forged firmware updates

Published Jul 7, 2025 · Updated Jul 7, 2025

CSRF in Arduino-ESP32 before 3.2.1 allows remote attackers to execute arbitrary firmware through a forged update request. The /update POST handlers in HTTPUpdateServer and two OTA examples accept firmware uploads without validating Origin against Host or using an anti-CSRF token. Exploitation requires a user on the device's local network to visit attacker-controlled web content; a successful upload replaces and runs device firmware.

CVSS severity9.4
Critical
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF in Arduino-ESP32 before 3.2.1 allows remote attackers to execute arbitrary firmware through a forged update request. The /update POST handlers in HTTPUpdateServer and two OTA examples accept firmware uploads without validating Origin against Host or using an anti-CSRF token. Exploitation requires a user on the device's local network to visit attacker-controlled web content; a successful upload replaces and runs device firmware.

The record

CVE
CVE-2025-53540
Published
Jul 7, 2025
Updated
Jul 7, 2025
Vendor
Espressif Systems
Product
Arduino-ESP32
Classifications
CWE-352, T1601.001, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 7, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Espressif Systems · Arduino-ESP32version=< 3.2.1

Published CVSS scores

9.4GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
T1601.001Modify System Image: Patch System Image
T1204.001User Execution: Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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