What is the CVSS score of CVE-2025-21485?

CVE-2025-21485 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of Fastconnect 6900 Firmware are affected by CVE-2025-21485?

CVE-2025-21485 is a high-severity memory corruption vulnerability affecting FastRPC processing that could allow attackers to crash systems or execute arbitrary code on affected infrastructure.

How to fix or mitigate CVE-2025-21485?

Within 24 hours: Identify and inventory all systems running FastRPC; assess exposure in production and non-production environments; establish incident response readiness. Within 7 days: Implement network segmentation to restrict FastRPC access; disable multimode invoke functionality if operationally feasible; deploy monitoring for abnormal IOCTL activity. Within 30 days: Establish vendor communication channel for patch availability; conduct threat modeling for FastRPC-dependent processes; develop rollout plan for patching once available.

Fastconnect 6900 Firmware CVE-2025-21485

EUVD-2025-16704 HIGH

Time-of-check Time-of-use (TOCTOU) Race Condition (CWE-367)

2025-06-03 product-security@qualcomm.com

Buffer Overflow Denial Of Service Memory Corruption Fastconnect 6900 Firmware Fastconnect 7800 Firmware Qmp1000 Firmware Sm8735 Firmware Sm8750 Firmware Sm8750p Firmware Snapdragon 8 Gen 3 Mobile Platform Firmware Sw5100 Firmware Sw5100p Firmware Sxr2230p Firmware Sxr2250p Firmware Sxr2330p Firmware Wcd9378 Firmware Wcd9380 Firmware Wcd9385 Firmware Wcd9390 Firmware Wcd9395 Firmware Wcn7750 Firmware Wcn7860 Firmware Wcn7861 Firmware Wcn7880 Firmware Wcn7881 Firmware Wsa8830 Firmware Wsa8832 Firmware Wsa8835 Firmware Wsa8840 Firmware Wsa8845 Firmware Wsa8845h Firmware

7.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

EUVD ID Assigned

Mar 14, 2026 - 17:04 euvd

EUVD-2025-16704

Analysis Generated

Mar 14, 2026 - 17:04 vuln.today

CVE Published

Jun 03, 2025 - 06:15 nvd

HIGH 7.8

DescriptionCVE.org

Memory corruption while processing INIT and multimode invoke IOCTL calls on FastRPC.

AnalysisAI

Memory corruption vulnerability in Qualcomm's FastRPC implementation that affects local privilege escalation through malformed INIT and multimode invoke IOCTL calls. An attacker with local access and basic user privileges can trigger memory corruption to achieve code execution with elevated privileges, potentially compromising system integrity and confidentiality. The vulnerability carries a CVSS 7.8 score indicating high severity, though exploitation requires local access and authenticated session context.

Technical ContextAI

FastRPC (Fast Remote Procedure Call) is a Qualcomm proprietary inter-process communication (IPC) mechanism used extensively in Snapdragon chipsets for communication between ARM processors and Qualcomm's Hexagon Digital Signal Processors (DSPs). The vulnerability exists in the kernel-space FastRPC driver's IOCTL handler, specifically in processing INIT and multimode invoke commands. The root cause is CWE-367 (Time-of-check Time-of-use Race Condition), indicating a race condition where validation checks on IOCTL parameters occur at different times than when those parameters are actually used, allowing an attacker to modify memory between validation and use. This affects Qualcomm SDM, SM, and MSM chipset families where FastRPC is the primary DSP communication interface. The vulnerability manifests in the kernel FastRPC subsystem (typically located at /dev/adsprpc-smd) which handles both synchronous and asynchronous RPC invocations.

RemediationAI

Immediate mitigation: (1) Apply kernel security patches from Qualcomm/OEM vendor (check device security bulletin for January 2025 or later); (2) On Android, ensure device is running latest security patch level; (3) Restrict shell access and local account creation on affected devices; (4) Monitor for suspicious FastRPC IOCTL calls via audit logs if available. Long-term fix: Patch must serialize IOCTL validation and execution using proper synchronization primitives (mutexes around parameter validation and dereferencing). Workarounds if patch unavailable: Disable FastRPC subsystem entirely (breaks DSP functionality—not practical), or use LSM/SELinux policies to restrict /dev/adsprpc-smd access to trusted processes only. Vendor advisory links: Check Qualcomm Security Updates page (security.qualcomm.com) for January 2025+ bulletins, cross-reference with OEM (Samsung, Google, etc.) security updates for specific device models.