CVE-2025-21456

Q: What is the severity of CVE-2025-21456?

CVE-2025-21456 has a CVSS score of 7.8 (HIGH). This vulnerability allows memory corruption when multiple threads concurrently call IOCTL commands to map/unmap buffers in Qualcomm drivers. Attackers could exploit this to execute arbitrary code or cause denial of service. Affected systems include devices using vulnerable Qualcomm chipsets and drivers.

7.8 HIGH

📋 TL;DR

This vulnerability allows memory corruption when multiple threads concurrently call IOCTL commands to map/unmap buffers in Qualcomm drivers. Attackers could exploit this to execute arbitrary code or cause denial of service. Affected systems include devices using vulnerable Qualcomm chipsets and drivers.

💻 Affected Systems

Products:

Qualcomm chipsets with vulnerable drivers

Versions: Specific versions not detailed in reference; check Qualcomm advisory for affected chipset/driver versions.

Operating Systems: Android, Linux-based systems using Qualcomm drivers

Default Config Vulnerable: ⚠️ Yes

Notes: Affects systems with Qualcomm hardware where multiple threads can concurrently access IOCTL buffer mapping functions.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Local privilege escalation to kernel-level code execution, potentially leading to complete system compromise.

🟠

Likely Case

System crash or denial of service through kernel panic or memory corruption.

🟢

If Mitigated

Limited impact if proper access controls restrict IOCTL access to privileged users only.

🌐 Internet-Facing: LOW - Requires local access to exploit via IOCTL interface.

🏢 Internal Only: MEDIUM - Local attackers or malicious applications could exploit this vulnerability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and ability to trigger concurrent IOCTL calls with specific timing.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check Qualcomm security bulletin for specific patched driver versions.

Vendor Advisory: https://docs.qualcomm.com/product/publicresources/securitybulletin/august-2025-bulletin.html

Restart Required: Yes

Instructions:

1. Check Qualcomm advisory for affected chipset/driver versions. 2. Obtain updated drivers from device manufacturer or Qualcomm. 3. Apply driver updates following manufacturer instructions. 4. Reboot system to load patched drivers.

🔧 Temporary Workarounds

Restrict IOCTL access

linux

Limit access to vulnerable IOCTL commands to privileged users only.

# Use SELinux/AppArmor policies to restrict IOCTL access
# Configure device permissions to limit non-privileged access

🧯 If You Can't Patch

Implement strict access controls to prevent non-privileged users from accessing IOCTL interfaces.
Monitor for unusual IOCTL activity and system crashes that could indicate exploitation attempts.

🔍 How to Verify

Check if Vulnerable:

Check Qualcomm chipset/driver version against affected versions in security bulletin.

Check Version:

# For Android/Linux: dmesg | grep -i qualcomm OR check /sys/class/... driver version files

Verify Fix Applied:

Verify driver version has been updated to patched version specified in Qualcomm advisory.

📡 Detection & Monitoring

Log Indicators:

Kernel panic logs
Memory corruption errors in dmesg/kernel logs
Multiple concurrent IOCTL calls from same process

Network Indicators:

None - local exploitation only

SIEM Query:

source="kernel" AND ("panic" OR "corruption" OR "IOCTL")

📊 Metadata

CVE ID: CVE-2025-21456

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-416

EPSS Score: 0.02% exploit probability (3.2th percentile)

Published: August 6, 2025

Last Updated: August 20, 2025

🔗 References

https://docs.qualcomm.com/product/publicresources/securitybulletin/august-2025-bulletin.html Vendor Advisory

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Ar8035 Firmware by Qualcomm

C V2x 9150 Firmware by Qualcomm

Fastconnect 6900 Firmware by Qualcomm

Fastconnect 7800 Firmware by Qualcomm

Qam8255p Firmware by Qualcomm

Qam8295p Firmware by Qualcomm

Qam8650p Firmware by Qualcomm

Qam8775p Firmware by Qualcomm

Qca6174a Firmware by Qualcomm

Qca6574au Firmware by Qualcomm

Qca6584au Firmware by Qualcomm

Qca6696 Firmware by Qualcomm

Qca6698aq Firmware by Qualcomm

Qca6797aq Firmware by Qualcomm

Qca8081 Firmware by Qualcomm

Qca8337 Firmware by Qualcomm

Qcc710 Firmware by Qualcomm

Qcn6224 Firmware by Qualcomm

Qcn6274 Firmware by Qualcomm

Qcs410 Firmware by Qualcomm

Qcs610 Firmware by Qualcomm

Qfw7114 Firmware by Qualcomm

Qfw7124 Firmware by Qualcomm

Sa6145p Firmware by Qualcomm

Sa6150p Firmware by Qualcomm

Sa6155p Firmware by Qualcomm

Sa7255p Firmware by Qualcomm

Sa7775p Firmware by Qualcomm

Sa8145p Firmware by Qualcomm

Sa8150p Firmware by Qualcomm

Sa8155p Firmware by Qualcomm

Sa8195p Firmware by Qualcomm

Sa8255p Firmware by Qualcomm

Sa8295p Firmware by Qualcomm

Sa8530p Firmware by Qualcomm

Sa8540p Firmware by Qualcomm

Sa8620p Firmware by Qualcomm

Sa8650p Firmware by Qualcomm

Sa8775p Firmware by Qualcomm

Sa9000p Firmware by Qualcomm

Snapdragon 888 5g Mobile Platform Firmware by Qualcomm

Snapdragon 888\+ 5g Mobile Platform \(sm8350 Ac\) Firmware by Qualcomm

Snapdragon Auto 5g Modem Rf Gen 2 Firmware by Qualcomm

Snapdragon W5\+ Gen 1 Wearable Platform Firmware by Qualcomm

Snapdragon X72 5g Modem Rf System Firmware by Qualcomm

Snapdragon X75 5g Modem Rf System Firmware by Qualcomm

Sw5100 Firmware by Qualcomm

Sw5100p Firmware by Qualcomm

Video Collaboration Vc1 Platform Firmware by Qualcomm

Video Collaboration Vc3 Platform Firmware by Qualcomm

Wcd9340 Firmware by Qualcomm

Wcd9341 Firmware by Qualcomm

Wcd9370 Firmware by Qualcomm

Wcd9380 Firmware by Qualcomm

Wcd9385 Firmware by Qualcomm

Wcn3660b Firmware by Qualcomm

Wcn3680b Firmware by Qualcomm

Wcn3950 Firmware by Qualcomm

Wcn3980 Firmware by Qualcomm

Wcn3988 Firmware by Qualcomm

Wsa8810 Firmware by Qualcomm

Wsa8815 Firmware by Qualcomm

Wsa8830 Firmware by Qualcomm

Wsa8835 Firmware by Qualcomm