// For flags

CVE-2025-52471

ESP-NOW Integer Underflow Vulnerability Advisory

Severity Score

7.2
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Attend
*SSVC
Descriptions

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. An integer underflow vulnerability has been identified in the ESP-NOW protocol implementation within the ESP Wi-Fi component of versions 5.4.1, 5.3.3, 5.2.5, and 5.1.6 of the ESP-IDF framework. This issue stems from insufficient validation of user-supplied data length in the packet receive function. Under certain conditions, this may lead to out-of-bounds memory access and may allow arbitrary memory write operations. On systems without a memory protection scheme, this behavior could potentially be used to achieve remote code execution (RCE) on the target device. In versions 5.4.2, 5.3.4, 5.2.6, and 5.1.6, ESP-NOW has added more comprehensive validation logic on user-supplied data length during packet reception to prevent integer underflow caused by negative value calculations. For ESP-IDF v5.3 and earlier, a workaround can be applied by validating that the `data_len` parameter received in the RX callback (registered via `esp_now_register_recv_cb()`) is a positive value before further processing. For ESP-IDF v5.4 and later, no application-level workaround is available. Users are advised to upgrade to a patched version of ESP-IDF to take advantage of the built-in mitigation.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
System
Vulnerable | Subsequent
Confidentiality
High
None
Integrity
High
None
Availability
High
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Attend
Exploitation
None
Automatable
Yes
Tech. Impact
Total
* Organization's Worst-case Scenario
Timeline
  • 2025-06-17 CVE Reserved
  • 2025-06-24 CVE Published
  • 2025-06-24 CVE Updated
  • 2025-06-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-191: Integer Underflow (Wrap or Wraparound)
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Espressif
Search vendor "Espressif"
Esp-idf
Search vendor "Espressif" for product "Esp-idf"
5.4.1
Search vendor "Espressif" for product "Esp-idf" and version "5.4.1"
en
Affected
Espressif
Search vendor "Espressif"
Esp-idf
Search vendor "Espressif" for product "Esp-idf"
5.3.3
Search vendor "Espressif" for product "Esp-idf" and version "5.3.3"
en
Affected
Espressif
Search vendor "Espressif"
Esp-idf
Search vendor "Espressif" for product "Esp-idf"
5.2.5
Search vendor "Espressif" for product "Esp-idf" and version "5.2.5"
en
Affected
Espressif
Search vendor "Espressif"
Esp-idf
Search vendor "Espressif" for product "Esp-idf"
5.1.6
Search vendor "Espressif" for product "Esp-idf" and version "5.1.6"
en
Affected