CVE-2025-24495: Intel Core Ultra Information Disclosure

CVE-2025-24495 Overview

CVE-2025-24495 is a hardware vulnerability affecting the branch prediction unit in Intel Core Ultra Processors. The flaw stems from incorrect initialization of resources within the branch prediction unit, which may allow an authenticated local user to potentially access sensitive information through side-channel attacks. This type of vulnerability is particularly concerning as it affects the fundamental hardware architecture and can potentially expose protected memory contents.

Critical Impact

Authenticated local attackers may exploit improper branch prediction unit initialization to potentially disclose sensitive information from protected memory regions across security boundaries.

Affected Products

• Intel® Core™ Ultra Processors (various models)
• Systems running Intel Core Ultra processor-based platforms
• Virtual environments and cloud instances using affected Intel processors

Discovery Timeline

• 2025-05-13 - CVE-2025-24495 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-24495

Vulnerability Analysis

This vulnerability represents a hardware-level flaw in Intel's branch prediction unit implementation within Core Ultra processors. Branch prediction units are critical CPU components that attempt to predict the outcome of conditional branches to improve instruction pipeline efficiency. When these units are not properly initialized, residual state information may persist and become accessible to authenticated users through carefully crafted local access patterns.

The vulnerability enables information disclosure through local access vectors. An attacker with local authentication could potentially leverage this flaw to extract sensitive data that would otherwise be protected by memory isolation mechanisms. This is characteristic of speculative execution vulnerabilities that have affected modern processors.

Root Cause

The root cause of CVE-2025-24495 is improper initialization of resources within the branch prediction unit. During processor state transitions or context switches, the branch prediction unit fails to properly clear or initialize internal state data. This leaves residual information that could be inferred through timing-based side-channel techniques, potentially allowing an authenticated user to reconstruct sensitive data from other processes or privilege levels.

Attack Vector

The attack requires local access and authentication on the target system. An attacker must be able to execute code locally on a system equipped with affected Intel Core Ultra processors. The exploitation complexity is considered high, as the attacker must carefully craft memory access patterns and timing measurements to extract meaningful information from the improperly initialized branch prediction state.

The attack does not require user interaction and operates at the hardware level, meaning traditional software-based protections may be insufficient without microcode updates or kernel-level mitigations. The scope extends beyond the vulnerable component, as successful exploitation could potentially disclose information from other security contexts.

Detection Methods for CVE-2025-24495

Indicators of Compromise

• Unusual patterns of memory access operations that may indicate side-channel probing attempts
• Unexpected timing variations in branch-heavy code execution
• Anomalous CPU performance counter readings related to branch prediction statistics
• Processes exhibiting cache timing measurement patterns characteristic of speculative execution attacks

Detection Strategies

• Monitor for processes performing high-frequency timing measurements using rdtsc or similar timing instructions
• Implement hardware performance counter monitoring to detect abnormal branch misprediction patterns
• Deploy endpoint detection solutions capable of identifying speculative execution attack patterns
• Review system logs for suspicious local user activity on systems with affected Intel Core Ultra processors

Monitoring Recommendations

• Enable Intel Processor Trace (PT) where available to monitor execution patterns
• Implement continuous monitoring of privileged memory access patterns
• Configure SentinelOne Singularity Platform to detect behavioral indicators associated with hardware side-channel exploitation
• Establish baseline branch prediction performance metrics to identify anomalous activity

How to Mitigate CVE-2025-24495

Immediate Actions Required

• Review the Intel Security Advisory SA-01322 for detailed mitigation guidance
• Apply available microcode updates from Intel as they become available
• Update system firmware and BIOS to incorporate latest processor mitigations
• Review the Debian LTS Announcement for Linux kernel updates addressing this vulnerability

Patch Information

Intel has released security guidance through Security Advisory SA-01322. Organizations should apply the following updates:

1. Microcode Updates: Install the latest Intel microcode updates available through your operating system's package manager or firmware update utilities
2. Kernel Updates: Apply kernel patches that implement software-level mitigations for branch prediction vulnerabilities
3. Firmware Updates: Check with system OEM vendors for BIOS/UEFI updates that incorporate the necessary microcode

Workarounds

• Restrict local access to systems containing sensitive workloads running on affected Intel Core Ultra processors
• Implement strict process isolation using containerization or virtualization with hardware-enforced boundaries
• Consider workload segregation to isolate sensitive processes from untrusted code execution
• Enable available kernel hardening options such as KPTI (Kernel Page Table Isolation) if applicable

# Check current Intel microcode version on Linux
cat /proc/cpuinfo | grep -i microcode

# Update microcode on Debian/Ubuntu systems
sudo apt update
sudo apt install intel-microcode

# Verify kernel mitigations status
cat /sys/devices/system/cpu/vulnerabilities/*