CVE-2021-40008
📋 TL;DR
This memory leak vulnerability in Huawei CloudEngine switches allows attackers to cause memory exhaustion by sending crafted binary messages. Affected organizations are those running specific Huawei CloudEngine switch models with vulnerable firmware versions. The vulnerability could lead to denial of service conditions.
💻 Affected Systems
- CloudEngine 12800
- CloudEngine 5800
- CloudEngine 6800
- CloudEngine 7800
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete memory exhaustion leading to switch crash and network outage, requiring physical reboot and service disruption.
Likely Case
Degraded switch performance, packet loss, and intermittent connectivity issues as memory becomes constrained.
If Mitigated
Minimal impact with proper network segmentation and monitoring; potential performance degradation but no complete outage.
🎯 Exploit Status
Exploitation requires crafting specific binary messages but does not require authentication. No public exploit code has been disclosed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V200R019C00SPC810 or later
Vendor Advisory: https://www.huawei.com/en/psirt/security-advisories/huawei-sa-20211208-01-memleak-en
Restart Required: Yes
Instructions:
1. Download the patched firmware from Huawei support portal. 2. Backup current configuration. 3. Upload and install the new firmware. 4. Reboot the switch. 5. Verify the new version is running.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to switch management interfaces to trusted networks only.
access-list 100 permit ip 10.0.0.0 0.255.255.255 any
interface vlanif 1
traffic-filter inbound acl 100
Rate Limiting
allImplement rate limiting on management interfaces to slow potential memory exhaustion attacks.
qos car inbound any cir 1000
interface vlanif 1
qos car inbound
🧯 If You Can't Patch
- Implement strict network access controls to limit who can communicate with switch management interfaces.
- Deploy network monitoring to detect abnormal traffic patterns or memory usage spikes on affected switches.
🔍 How to Verify
Check if Vulnerable:
Check firmware version with: display version | include V200R019C00SPC800Check Version:
display versionVerify Fix Applied:
Verify firmware version is V200R019C00SPC810 or later: display version | include V200R019C00SPC📡 Detection & Monitoring
Log Indicators:
- Memory usage spikes in system logs
- Repeated connection attempts to switch management interfaces
- System warning messages about memory exhaustion
Network Indicators:
- Unusual volume of binary traffic to switch management ports
- Abnormal packet patterns targeting switch management interfaces
SIEM Query:
source="switch_logs" AND ("memory" AND "exhaust" OR "high" AND "usage")