CVE-2025-9557
📋 TL;DR
CVE-2025-9557 is a buffer overflow vulnerability in Zephyr RTOS that allows attackers to write beyond allocated memory boundaries. This can lead to arbitrary code execution or denial of service through system crashes. Affects devices running vulnerable versions of Zephyr RTOS.
💻 Affected Systems
- Zephyr RTOS
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with remote code execution leading to complete device control and data exfiltration.
Likely Case
System crash and denial of service, potentially requiring physical reset or maintenance.
If Mitigated
Controlled crash with minimal service disruption if memory protection features are enabled.
🎯 Exploit Status
Exploitation requires specific conditions and knowledge of the target system. No public exploits available at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Zephyr security advisory for specific patched versions
Vendor Advisory: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r3j3-c5v7-2ppf
Restart Required: Yes
Instructions:
1. Review Zephyr security advisory GHSA-r3j3-c5v7-2ppf
2. Update Zephyr RTOS to patched version
3. Rebuild and redeploy firmware
4. Restart affected devices
🔧 Temporary Workarounds
Enable memory protection features
allActivate hardware memory protection units (MPU) or software memory protection if available
Configure CONFIG_HW_STACK_PROTECTION=y in Zephyr configuration
Enable CONFIG_MPU=y if hardware supports it
Input validation hardening
allAdd additional bounds checking in application code
Implement manual bounds checking before buffer operations
Use safe string functions where available
🧯 If You Can't Patch
- Isolate affected devices from untrusted networks
- Implement network segmentation to limit blast radius
🔍 How to Verify
Check if Vulnerable:
Check Zephyr version against advisory and review code for buffer operations without proper bounds checkingCheck Version:
Check Zephyr build configuration and version headersVerify Fix Applied:
Verify Zephyr version is updated beyond vulnerable versions and test buffer overflow scenarios📡 Detection & Monitoring
Log Indicators:
- System crashes or reboots
- Memory access violation logs
- Unexpected process termination
Network Indicators:
- Unusual network traffic from embedded devices
- Protocol anomalies in device communications
SIEM Query:
device_type:embedded AND (event_type:crash OR memory_violation) AND os:zephyr