CVE-2025-63094
📋 TL;DR
This CVE describes a Spectre-style speculative execution vulnerability in XiangShan RISC-V processors that allows attackers to extract sensitive information via cache side-channel attacks. It affects systems using XiangShan Nanhu V2 and Kunmighu V3 processor cores. The vulnerability enables unauthorized access to memory contents that should be protected.
💻 Affected Systems
- XiangShan Nanhu V2
- XiangShan Kunmighu V3
📦 What is this software?
Xiangshan by Xiangshan
Xiangshan by Xiangshan
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of sensitive data including encryption keys, passwords, and proprietary information from memory across security boundaries.
Likely Case
Information leakage from shared cloud environments or multi-tenant systems where attackers can run malicious code on the same physical hardware.
If Mitigated
Limited impact with proper isolation controls, but still vulnerable to determined attackers with local access.
🎯 Exploit Status
Proof-of-concept code is available on GitHub. Exploitation requires local code execution but leverages well-known Spectre attack patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not applicable - hardware vulnerability
Vendor Advisory: No vendor advisory found
Restart Required: No
Instructions:
This is a hardware vulnerability. Contact XiangShan developers for information about processor revisions or microcode updates. Consider replacing affected hardware if available.
🔧 Temporary Workarounds
Disable speculative execution features
linuxDisable branch prediction and speculative execution at kernel level if supported
echo 1 > /sys/kernel/debug/x86/spectre_v2
echo 2 > /proc/sys/kernel/spectre_v2_user
Apply software mitigations
allImplement software-based Spectre mitigations in applications and system software
🧯 If You Can't Patch
- Isolate sensitive workloads on separate physical hardware
- Implement strict access controls and monitoring for systems with affected processors
🔍 How to Verify
Check if Vulnerable:
Check processor model: cat /proc/cpuinfo | grep 'model name' and verify if it contains XiangShan Nanhu V2 or Kunmighu V3Check Version:
cat /proc/cpuinfo | grep -i 'xiangshan'Verify Fix Applied:
No software fix available. Verify hardware replacement or microcode updates from vendor.📡 Detection & Monitoring
Log Indicators:
- Unusual cache access patterns
- Suspicious speculative execution test programs
Network Indicators:
- Not network exploitable - local vulnerability only
SIEM Query:
Process execution of known Spectre PoC tools or unusual cache monitoring utilities