CVE-2025-27807
📋 TL;DR
A critical vulnerability in multiple Samsung Exynos processors allows attackers to execute arbitrary code or cause denial of service via malformed NAS packets due to missing length checks. This affects Samsung mobile devices, wearables, and modems using the listed Exynos chips. Attackers can exploit this remotely without authentication.
💻 Affected Systems
- Samsung Mobile Processor
- Samsung Wearable Processor
- Samsung Modem
- Exynos 980
- Exynos 990
- Exynos 850
- Exynos 1080
- Exynos 2100
- Exynos 1280
- Exynos 2200
- Exynos 1330
- Exynos 1380
- Exynos 1480
- Exynos 2400
- Exynos 1580
- Exynos 9110
- Exynos W920
- Exynos W930
- Exynos W1000
- Modem 5123
- Modem 5300
- Modem 5400
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise allowing remote code execution, data theft, persistent backdoor installation, or complete device bricking.
Likely Case
Device crashes, denial of service, or limited code execution leading to data exfiltration or further privilege escalation.
If Mitigated
Limited impact if network segmentation and strict access controls prevent malicious packet delivery to vulnerable devices.
🎯 Exploit Status
Exploitation requires crafting malformed NAS packets and delivering them to vulnerable devices, typically via cellular networks or local network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Vendor-specific firmware updates
Vendor Advisory: https://semiconductor.samsung.com/support/quality-support/product-security-updates/cve-2025-27807/
Restart Required: Yes
Instructions:
1. Check for device manufacturer firmware updates. 2. Apply the latest security patch from Samsung or device OEM. 3. Reboot device after update. 4. Verify patch installation in device settings.
🔧 Temporary Workarounds
Network segmentation
allIsolate vulnerable devices from untrusted networks to prevent malicious packet delivery.
Disable unnecessary cellular features
allTurn off cellular data when not needed or use Wi-Fi only mode to reduce attack surface.
🧯 If You Can't Patch
- Replace affected devices with patched or non-vulnerable hardware
- Implement strict network access controls and monitoring for suspicious NAS traffic
🔍 How to Verify
Check if Vulnerable:
Check device model and chipset in settings > about phone > hardware info. Compare with affected products list.Check Version:
Settings > About phone > Software information > Build number / Baseband versionVerify Fix Applied:
Verify firmware version matches or exceeds the patched version provided by manufacturer in security bulletin.📡 Detection & Monitoring
Log Indicators:
- Unexpected device crashes or reboots
- Kernel panic logs related to NAS processing
- Modem subsystem errors
Network Indicators:
- Unusual NAS packet patterns from untrusted sources
- Spike in malformed packet drops at network perimeter
SIEM Query:
source="device_logs" AND (event_type="crash" OR event_type="kernel_panic") AND process="modem"