CVE-2021-22439
📋 TL;DR
This CVE describes a deserialization vulnerability in Huawei AnyOffice that allows remote code execution. Attackers can send crafted requests to exploit it, potentially taking full control of affected devices. Organizations using the vulnerable Huawei AnyOffice version are at risk.
💻 Affected Systems
- Huawei AnyOffice
📦 What is this software?
Anyoffice by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of the device, enabling attackers to execute arbitrary code, steal data, pivot to other systems, or disrupt operations.
Likely Case
Remote code execution leading to unauthorized access, data exfiltration, or installation of malware on the device.
If Mitigated
Limited impact if patched or isolated; attackers may fail to exploit due to network segmentation or other controls.
🎯 Exploit Status
Exploitation requires crafting specific requests, but no public proof-of-concept is known; unauthenticated access suggests lower barrier.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not explicitly stated in references; check Huawei advisory for updated versions.
Vendor Advisory: https://www.huawei.com/en/psirt/security-advisories/huawei-sa-20210619-01-injection-en
Restart Required: Yes
Instructions:
1. Review Huawei advisory for patch details. 2. Download and apply the recommended update from Huawei. 3. Restart the AnyOffice service or device as required. 4. Verify the fix using version checks.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to Huawei AnyOffice to trusted IPs only, reducing exposure to potential attackers.
Use firewall rules to allow only necessary traffic (e.g., iptables -A INPUT -s trusted_ip -p tcp --dport anyoffice_port -j ACCEPT on Linux).
🧯 If You Can't Patch
- Isolate the affected system from critical networks to limit lateral movement.
- Monitor logs and network traffic for unusual activity indicative of exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check the Huawei AnyOffice version; if it is V200R006C10, it is vulnerable. Use system logs or management interfaces.Check Version:
Consult Huawei AnyOffice documentation or administrative console for version command (e.g., anyoffice --version or similar).Verify Fix Applied:
After patching, confirm the version has been updated to a non-vulnerable release as per Huawei's advisory.📡 Detection & Monitoring
Log Indicators:
- Unusual deserialization errors, unexpected process executions, or anomalous network requests to AnyOffice services.
Network Indicators:
- Suspicious inbound traffic to AnyOffice ports, especially crafted payloads indicative of exploitation.
SIEM Query:
Example: 'source="anyoffice_logs" AND (event_type="deserialization_error" OR process="malicious_executable")'