CVE-2025-26785 Overview
An out-of-bounds write vulnerability has been discovered in the Non-Access Stratum (NAS) component of Samsung Exynos mobile processors, wearable processors, and modems. The vulnerability stems from a missing length check in NAS message processing, which allows attackers to write data beyond allocated buffer boundaries. This flaw affects a wide range of Samsung semiconductor products used in smartphones, wearables, and communication devices.
Critical Impact
Remote attackers can trigger denial of service conditions on affected devices by exploiting the out-of-bounds write vulnerability through specially crafted network packets targeting the NAS layer.
Affected Products
- Samsung Exynos Mobile Processors (980, 990, 850, 1080, 2100, 1280, 2200, 1330, 1380, 1480, 2400)
- Samsung Exynos Wearable Processors (W920, W930, W1000, 9110)
- Samsung Exynos Modems (5123, 5300, 5400)
Discovery Timeline
- May 14, 2025 - CVE-2025-26785 published to NVD
- June 25, 2025 - Last updated in NVD database
Technical Details for CVE-2025-26785
Vulnerability Analysis
This vulnerability is classified as CWE-787 (Out-of-Bounds Write). The flaw exists within the Non-Access Stratum (NAS) protocol handling component of Samsung Exynos chipsets. NAS is a fundamental layer in cellular network communication responsible for managing signaling between mobile devices and the core network for tasks such as mobility management, session management, and authentication.
The vulnerability allows remote exploitation over a network connection without requiring any user interaction or authentication. When successfully exploited, an attacker can cause denial of service conditions affecting device availability. The impact is limited to availability—there is no evidence of confidentiality or integrity compromise from this specific vulnerability.
Root Cause
The root cause of CVE-2025-26785 is a missing length validation check in the NAS message parsing functionality. When processing incoming NAS protocol messages, the firmware fails to verify that the length of received data fields does not exceed the boundaries of allocated memory buffers. This allows malformed or maliciously crafted NAS messages to write data beyond the intended buffer limits, corrupting adjacent memory regions and potentially crashing the baseband processor.
Attack Vector
The vulnerability can be exploited remotely over the cellular network. An attacker positioned on the network path (such as a rogue base station or through man-in-the-middle positioning) can send specially crafted NAS protocol messages to vulnerable devices. The attack requires no privileges on the target device and no user interaction, making it particularly concerning for mobile device security.
The attack targets the baseband processor's firmware, which operates independently from the application processor running the main operating system. This isolation means that while the vulnerability may cause denial of service to cellular connectivity, it is contained within the baseband subsystem.
Detection Methods for CVE-2025-26785
Indicators of Compromise
- Unexpected device reboots or cellular connectivity drops without user action
- Baseband processor crashes logged in device diagnostics
- Abnormal cellular signaling behavior detected by network operators
- Device becoming unresponsive specifically during cellular network operations
Detection Strategies
- Monitor device logs for baseband crash events or modem firmware exceptions
- Implement network-level detection for malformed NAS protocol messages with abnormal length fields
- Deploy endpoint detection solutions capable of monitoring baseband processor health
- Utilize SentinelOne Singularity Mobile to monitor for anomalous device behavior patterns
Monitoring Recommendations
- Enable verbose logging for cellular modem events on enterprise-managed mobile devices
- Configure alerting for repeated baseband processor restarts
- Monitor fleet-wide device health for patterns suggesting coordinated attacks
- Coordinate with mobile network operators for suspicious signaling activity alerts
How to Mitigate CVE-2025-26785
Immediate Actions Required
- Apply firmware updates from Samsung as soon as they become available for affected Exynos chipsets
- Review the Samsung Security Advisory for specific patch guidance
- Prioritize updating devices with critical business functions or access to sensitive data
- Consider network-level protections where feasible in enterprise environments
Patch Information
Samsung has acknowledged this vulnerability and published security update information through their semiconductor security portal. Organizations should consult the Samsung Product Security Updates page for the latest firmware versions addressing CVE-2025-26785. Device manufacturers using affected Exynos chipsets (including Samsung smartphones, wearables, and third-party devices) will need to distribute updates through their respective update channels.
Workarounds
- No complete workarounds are available as the vulnerability exists in baseband firmware
- Minimize exposure to untrusted cellular networks where feasible
- Use Wi-Fi connectivity when in potentially hostile cellular environments
- Deploy mobile threat defense solutions to detect anomalous device behavior
- Consider network segmentation for critical mobile device fleets
# Verify current firmware version on Android devices with Exynos processors
# Settings > About phone > Baseband version
# Compare against Samsung security bulletin to confirm patch status
adb shell getprop gsm.version.baseband
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
