USN-8574-3: Linux Kernel AMD Processor Vulnerabilities — Detection and Remediation Guide

---
title: Potential Exploitation of AMD Processor Speculative Execution Vulnerability
id: 8a7f5c2d-3e4b-4a1d-9c2e-5f6a7b8c9d0e
status: experimental
description: Detects potential exploitation attempts of AMD speculative execution vulnerability via suspicious timing or side-channel measurement tools
references:
  - https://ubuntu.com/security/notices/USN-8574-3
  - CVE-2025-54505
author: Security Arsenal
date: 2026/02/12
tags:
  - attack.execution
  - attack.t1059.004
logsource:
  category: process_creation
  product: linux
detection:
  selection_tools:
    Image|endswith:
      - '/perf'
      - '/rdmsr'
      - '/wrmsr'
  selection_timing:
    CommandLine|contains:
      - 'cache-line'
      - 'side-channel'
      - 'flush+reload'
      - 'prefetch'
  condition: 1 of selection*
falsepositives:
  - Legitimate performance testing
  - System benchmarking tools
level: medium
---
title: Potential AMD Zen 2 Operation Cache Privilege Escalation Attempt
id: 9b8e6d3f-4f5c-5b2e-0d3f-6a7b8c9d0e1f
status: experimental
description: Detects potential attempts to exploit AMD Zen 2 operation cache vulnerability leading to privilege escalation
references:
  - https://ubuntu.com/security/notices/USN-8574-3
  - CVE-2025-54518
author: Security Arsenal
date: 2026/02/12
tags:
  - attack.privilege_escalation
  - attack.t1068
logsource:
  category: process_creation
  product: linux
detection:
  selection_suid:
    CommandLine|contains:
      - 'gcc -fPIC -shared'
      - 'LD_PRELOAD'
  selection_exploit:
    CommandLine|contains:
      - 'zen2'
      - 'op_cache'
      - 'transient_exec'
  condition: selection_suid and selection_exploit
falsepositives:
  - Legitimate software development
level: high

// Hunt for vulnerable kernel versions and potential exploitation attempts
// Check for systems running vulnerable Linux kernel versions
let VulnerableKernels = dynamic([
  "5.15.0-126", "5.4.0-189", "6.8.0-45", "6.11.0-13"
]);
Syslog
| where SyslogMessage contains "Linux version"
| extend KernelVersion = extract(@"Linux version ([\d\.\-]+)", 1, SyslogMessage)
| where KernelVersion !in ("", "null")
| extend MajorMinor = extract(@"^([\d\.]+)", 1, KernelVersion)
| where KernelVersion has_any (VulnerableKernels) or 
        (MajorMinor == "5.15" and toint(extract(@"\-([0-9]+)$", 1, KernelVersion)) < 126) or
        (MajorMinor == "5.4" and toint(extract(@"\-([0-9]+)$", 1, KernelVersion)) < 189) or
        (MajorMinor == "6.8" and toint(extract(@"\-([0-9]+)$", 1, KernelVersion)) < 45) or
        (MajorMinor == "6.11" and toint(extract(@"\-([0-9]+)$", 1, KernelVersion)) < 13)
| project TimeGenerated, HostName, IPAddress, KernelVersion, MajorMinor, _ResourceId
| distinct TimeGenerated, HostName, KernelVersion, _ResourceId
| order by TimeGenerated desc

-- Hunt for vulnerable kernel versions and AMD processors
SELECT 
  OSInfo.Hostname as Hostname,
  OSInfo.KernelVersion as KernelVersion,
  CPUInfo.Model as CPUModel,
  CPUInfo.Vendor as CPUVendor,
  CPUInfo.Family as CPUFamily,
  CPUInfo.ModelNumber as CPUModelNumber
FROM source(
    artifact="Linux.System.Info/OSInfo"
  )
LEFT JOIN ON Hostname = Hostname (
    SELECT 
      Hostname,
      Model,
      Vendor,
      Family,
      ModelNumber
    FROM source(
      artifact="Linux.System.Info/CPUInfo"
    )
)
WHERE CPUVendor =~ "AMD"
  AND (
    KernelVersion =~ "^5.15.0-1[0-2][0-9].*" OR
    KernelVersion =~ "^5.4.0-1[0-8][0-9].*" OR
    KernelVersion =~ "^6.8.0-4[0-4].*" OR
    KernelVersion =~ "^6.11.0-1[0-3].*"
  )
ORDER BY Hostname

#!/bin/bash
# Remediation script for USN-8574-3 AMD processor vulnerabilities
# Check for vulnerable kernel versions and apply updates

# Function to check current kernel version
check_kernel_version() {
    CURRENT_KERNEL=$(uname -r)
    echo "Current kernel version: $CURRENT_KERNEL"
}

# Function to check if running on vulnerable AMD processor
check_amd_processor() {
    CPU_VENDOR=$(lscpu | grep "Vendor ID" | awk '{print $3}')
    if [[ "$CPU_VENDOR" == "AuthenticAMD" ]]; then
        CPU_MODEL=$(lscpu | grep "Model name" | awk -F: '{print $2}' | xargs)
        echo "System running on AMD processor: $CPU_MODEL"
        
        # Check for Zen 2 processors specifically vulnerable to CVE-2025-54518
        if lscpu | grep -qi "zen 2\|ryzen 3000\|ryzen 4000\|epyc 7002"; then
            echo "WARNING: This system is running a Zen 2 processor vulnerable to CVE-2025-54518"
            return 2
        fi
        return 1
    else
        echo "System is not running on AMD processor"
        return 0
    fi
}

# Function to check if kernel is vulnerable
check_vulnerability() {
    KERNEL=$(uname -r)
    
    # Ubuntu 22.04 LTS (5.15 kernel)
    if [[ "$KERNEL" =~ ^5.15.0- ]]; then
        KERNEL_BUILD=$(echo "$KERNEL" | cut -d- -f2 | cut -d. -f1)
        if [[ $KERNEL_BUILD -lt 126 ]]; then
            echo "VULNERABLE: Ubuntu 22.04 with kernel $KERNEL"
            return 1
        fi
    fi
    
    # Ubuntu 20.04 LTS (5.4 kernel)
    if [[ "$KERNEL" =~ ^5.4.0- ]]; then
        KERNEL_BUILD=$(echo "$KERNEL" | cut -d- -f2 | cut -d. -f1)
        if [[ $KERNEL_BUILD -lt 189 ]]; then
            echo "VULNERABLE: Ubuntu 20.04 with kernel $KERNEL"
            return 1
        fi
    fi
    
    # Ubuntu 24.04 LTS (6.8 kernel)
    if [[ "$KERNEL" =~ ^6.8.0- ]]; then
        KERNEL_BUILD=$(echo "$KERNEL" | cut -d- -f2 | cut -d. -f1)
        if [[ $KERNEL_BUILD -lt 45 ]]; then
            echo "VULNERABLE: Ubuntu 24.04 with kernel $KERNEL"
            return 1
        fi
    fi
    
    # Ubuntu 24.10 (6.11 kernel)
    if [[ "$KERNEL" =~ ^6.11.0- ]]; then
        KERNEL_BUILD=$(echo "$KERNEL" | cut -d- -f2 | cut -d. -f1)
        if [[ $KERNEL_BUILD -lt 13 ]]; then
            echo "VULNERABLE: Ubuntu 24.10 with kernel $KERNEL"
            return 1
        fi
    fi
    
    echo "NOT VULNERABLE: Kernel $KERNEL is patched"
    return 0
}

# Function to apply updates
apply_updates() {
    echo "Applying security updates..."
    
    # Update package lists
    apt-get update -qq
    
    # Install kernel security updates
    if apt-get install -y linux-image-generic; then
        echo "Kernel updates installed successfully"
        echo "A system reboot will be required to activate the new kernel"
        return 0
    else
        echo "ERROR: Failed to install kernel updates"
        return 1
    fi
}

# Main execution
main() {
    echo "========================================"
    echo "USN-8574-3 AMD Vulnerability Remediation"
    echo "========================================"
    echo ""
    
    check_kernel_version
    check_amd_processor
    AMD_STATUS=$?
    
    if [[ $AMD_STATUS -eq 0 ]]; then
        echo "System is not affected by these AMD-specific vulnerabilities"
        exit 0
    fi
    
    check_vulnerability
    VULN_STATUS=$?
    
    if [[ $VULN_STATUS -eq 0 ]]; then
        echo "System is not vulnerable to these issues"
        exit 0
    fi
    
    echo ""
    echo "System is vulnerable to one or more AMD processor vulnerabilities"
    echo ""
    
    read -p "Do you want to apply security updates now? (y/n) " -n 1 -r
    echo
    
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        if apply_updates; then
            echo ""
            echo "Updates applied successfully. Please schedule a reboot to activate the new kernel."
        else
            echo ""
            echo "Failed to apply updates. Please run 'apt-get update && apt-get upgrade' manually."
            exit 1
        fi
    else
        echo "Updates cancelled. Please apply them manually as soon as possible."
        exit 1
    fi
}

main