CVE-2026-25532
📋 TL;DR
This vulnerability in ESP-IDF's WPS Enrollee implementation allows integer underflow when processing malformed EAP-WSC packets with truncated payloads. An attacker can cause memory corruption by sending specially crafted packets, potentially leading to denial of service or remote code execution. Affected systems include IoT devices using ESP-IDF versions 5.5.2, 5.4.3, 5.3.4, 5.2.6, and 5.1.6.
💻 Affected Systems
- Espressif IoT Development Framework (ESP-IDF)
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, data exfiltration, or device becoming part of botnet
Likely Case
Denial of service causing device crashes or instability, potentially requiring physical reset
If Mitigated
Limited impact if network segmentation prevents attacker access to vulnerable devices
🎯 Exploit Status
Exploitation requires sending malformed EAP-WSC packets to vulnerable devices
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.5.3, 5.4.4, 5.3.5, 5.2.7, 5.1.7
Vendor Advisory: https://github.com/espressif/esp-idf/security/advisories
Restart Required: Yes
Instructions:
1. Update ESP-IDF to patched version using 'git checkout' to appropriate release tag. 2. Rebuild and flash firmware to affected devices. 3. Verify WPS functionality works correctly after update.
🔧 Temporary Workarounds
Disable WPS Enrollee
allDisable WPS functionality in device configuration
# In sdkconfig: CONFIG_ESP_WIFI_ENABLE_WPS=n
Network Segmentation
allIsolate vulnerable devices from untrusted networks
🧯 If You Can't Patch
- Disable WPS functionality completely in device firmware
- Implement network access controls to restrict who can send WPS packets to vulnerable devices
🔍 How to Verify
Check if Vulnerable:
Check ESP-IDF version in firmware or build configuration. Vulnerable if using affected versions with WPS enabled.Check Version:
grep -r 'IDF_VER' build/config/sdkconfig.h or check ESP-IDF git tagVerify Fix Applied:
Verify ESP-IDF version is 5.5.3, 5.4.4, 5.3.5, 5.2.7, or 5.1.7. Test WPS functionality to ensure it works without crashes.📡 Detection & Monitoring
Log Indicators:
- Device crashes or reboots during WPS operations
- Memory corruption errors in system logs
Network Indicators:
- Malformed EAP-WSC packets with truncated payloads
- Unusual WPS traffic patterns
SIEM Query:
network.protocol:eap AND network.wps:true AND packet.size:<min_expected_size🔗 References
- https://github.com/espressif/esp-idf/commit/60f992a26de17bb5406f2149a2f8282dd7ad1c59
- https://github.com/espressif/esp-idf/commit/6f6766f917bc940ffbcc97eac4765a6ab15d5f79
- https://github.com/espressif/esp-idf/commit/73a587d42a57ece1962b6a4c530b574600650f63
- https://github.com/espressif/esp-idf/commit/b209fae993d795255827ce6b2b0d6942a377f5d4
- https://github.com/espressif/esp-idf/commit/b88befde6b5addcdd8d7373ce55c8052dea1e855
- https://github.com/espressif/esp-idf/commit/cad36beb4cde27abcf316cd90d8d8dddbc6f213a
- https://github.com/espressif/esp-idf/commit/de28801e8ea6a736b6f0db6fc0c682739363bb41
- https://github.com/espressif/esp-idf/security/advisories/GHSA-m2h2-683f-9mw7
