CVE-2020-1863
📋 TL;DR
This CVE describes an out-of-bounds read vulnerability in Huawei USG6000V firewall software due to a logical flaw in JSON parsing. Remote, unauthenticated attackers can exploit this vulnerability to cause denial of service by disrupting affected products. Organizations running specific versions of Huawei USG6000V firewalls are affected.
💻 Affected Systems
- Huawei USG6000V
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption of the firewall, potentially causing network outages and loss of security monitoring/protection capabilities.
Likely Case
Denial of service affecting firewall functionality, requiring reboot or manual intervention to restore service.
If Mitigated
Minimal impact if firewalls are behind additional security layers or have restricted access, though service disruption risk remains.
🎯 Exploit Status
Exploitation requires crafting malicious JSON payloads to trigger the out-of-bounds read condition.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Huawei security advisory for specific patched versions
Vendor Advisory: https://www.huawei.com/en/psirt/security-advisories/huawei-sa-20200311-01-buffer-en
Restart Required: Yes
Instructions:
1. Review Huawei security advisory SA-20200311-01. 2. Download appropriate patch from Huawei support portal. 3. Apply patch following Huawei's upgrade procedures. 4. Reboot device as required.
🔧 Temporary Workarounds
Restrict network access
allLimit access to firewall management interfaces to trusted networks only
Implement network segmentation
allPlace firewalls behind additional security layers to limit exposure
🧯 If You Can't Patch
- Isolate affected firewalls from untrusted networks
- Implement strict network access controls and monitor for anomalous JSON traffic
🔍 How to Verify
Check if Vulnerable:
Check firewall version via web interface or CLI: display versionCheck Version:
display versionVerify Fix Applied:
Verify version after patch application and confirm no service disruptions from test JSON payloads📡 Detection & Monitoring
Log Indicators:
- Unexpected firewall restarts
- JSON parsing errors in system logs
- Service disruption alerts
Network Indicators:
- Malformed JSON traffic to firewall management interfaces
- Unusual traffic patterns to firewall
SIEM Query:
firewall_service_disruption OR json_parsing_error OR usg6000v_restart