CVE-2023-21671 Overview
CVE-2023-21671 is a memory corruption vulnerability affecting Qualcomm chipset firmware. The vulnerability exists in the Core component during syscall operations for the Sectools Fuse comparison feature. A local attacker with low privileges can exploit this flaw to achieve unauthorized access to sensitive data, modify system information, or cause system instability on affected devices.
Critical Impact
Memory corruption in the Sectools Fuse comparison syscall can allow local attackers to compromise confidentiality, integrity, and availability of affected Qualcomm-powered devices including smartphones, IoT devices, and compute platforms.
Affected Products
- Qualcomm Snapdragon 888 5G Mobile Platform and Snapdragon 888+ 5G Mobile Platform
- Qualcomm Snapdragon 778G/780G/782G 5G Mobile Platforms
- Qualcomm Snapdragon 7c+ Gen 3 Compute Platform
- Qualcomm FastConnect 6700 and FastConnect 6900 Firmware
- Qualcomm QCM6490 and QCS6490 Chipsets
- Qualcomm WCD9370/WCD9375/WCD9380/WCD9385 Audio Codecs
- Qualcomm WCN6740 Connectivity Firmware
- Qualcomm WSA8830/WSA8835 Audio Amplifiers
- Qualcomm Video Collaboration VC3 Platform
Discovery Timeline
- November 7, 2023 - CVE-2023-21671 published to NVD
- August 11, 2025 - Last updated in NVD database
Technical Details for CVE-2023-21671
Vulnerability Analysis
This vulnerability stems from improper input validation (CWE-20) within the Qualcomm Core component. The flaw manifests when processing syscalls related to the Sectools Fuse comparison feature, a security-critical function used for hardware fuse verification and secure boot operations.
The memory corruption occurs at the kernel/firmware level, making it particularly dangerous as it operates below the typical application security boundaries. The local attack vector means an attacker would need some form of initial access to the device, such as through a malicious application or physical access. Once exploited, the vulnerability can lead to complete compromise of the affected system's confidentiality, integrity, and availability.
Given the widespread deployment of affected Snapdragon chipsets across Android smartphones, tablets, laptops, and IoT devices, the potential impact surface is substantial.
Root Cause
The root cause of CVE-2023-21671 is improper input validation in the syscall handler for the Sectools Fuse comparison feature. When processing fuse comparison requests, the Core component fails to properly validate input parameters before performing memory operations. This allows crafted input to trigger memory corruption, potentially leading to arbitrary code execution or privilege escalation within the secure execution environment.
Attack Vector
The attack requires local access to the vulnerable device. An attacker must execute code on the target system, typically through a malicious application or by exploiting another vulnerability to gain initial foothold. The attack does not require user interaction beyond installing or running the malicious component.
The attacker crafts malicious syscall parameters targeting the Sectools Fuse comparison functionality. When the vulnerable firmware processes these malformed inputs, memory corruption occurs within the privileged security context. This can be leveraged to escalate privileges, extract sensitive fuse data, or compromise the secure boot chain.
Detection Methods for CVE-2023-21671
Indicators of Compromise
- Unusual syscall patterns targeting secure enclave or TrustZone functions
- Abnormal memory access patterns in kernel logs related to fuse operations
- Unexpected crashes or kernel panics in security-related subsystems
- Signs of privilege escalation from application to kernel/firmware level
Detection Strategies
- Monitor system logs for anomalous behavior in Qualcomm-specific security components
- Implement endpoint detection rules for suspicious syscall sequences targeting secure firmware
- Deploy mobile threat defense solutions capable of detecting firmware-level exploitation attempts
- Analyze application behavior for attempts to interact with low-level security features
Monitoring Recommendations
- Enable verbose logging for secure boot and TrustZone operations where supported
- Deploy SentinelOne Singularity Mobile for comprehensive mobile endpoint protection
- Monitor for unusual application privilege requests related to hardware security features
- Implement network-level monitoring for potential exfiltration following device compromise
How to Mitigate CVE-2023-21671
Immediate Actions Required
- Apply firmware updates from device OEMs that incorporate the Qualcomm November 2023 security patches
- Review installed applications and remove any untrusted or unnecessary software
- Enable automatic security updates on affected devices
- Consider enterprise MDM policies to enforce minimum firmware versions
Patch Information
Qualcomm has addressed this vulnerability in their November 2023 security bulletin. Device manufacturers (OEMs) must integrate these patches into their firmware updates and distribute them to end users. Users should check their device manufacturer's support pages for available security updates.
For detailed patch information, refer to the Qualcomm November 2023 Security Bulletin.
Workarounds
- Restrict installation of applications to trusted sources only (official app stores)
- Implement mobile device management (MDM) policies to control application permissions
- Disable developer options and USB debugging on production devices
- Consider network segmentation for devices that cannot be immediately patched
# Android device security check (for enterprise MDM)
# Verify device security patch level is November 2023 or later
adb shell getprop ro.build.version.security_patch
# Expected output: 2023-11-01 or later
# Check for Qualcomm chipset information
adb shell cat /proc/cpuinfo | grep -i qualcomm
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
