CVE-2022-26993
📋 TL;DR
This CVE describes a command injection vulnerability in Arris routers that allows attackers to execute arbitrary system commands by manipulating PPPoE authentication parameters. Attackers can gain full control of affected routers through crafted network requests. Users of specific Arris router models with vulnerable firmware versions are affected.
💻 Affected Systems
- Arris SBR-AC1900P
- Arris SBR-AC3200P
- Arris SBR-AC1200P
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attacker to intercept all network traffic, install persistent malware, pivot to internal networks, and use router as attack platform.
Likely Case
Router takeover enabling traffic interception, credential theft, DNS manipulation, and network disruption.
If Mitigated
Limited impact if routers are behind firewalls with strict ingress filtering and not internet-facing.
🎯 Exploit Status
Public proof-of-concept available; exploitation requires sending crafted HTTP requests to router web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not publicly available
Restart Required: Yes
Instructions:
1. Check Arris support site for firmware updates
2. Download latest firmware for your model
3. Access router admin interface
4. Navigate to firmware update section
5. Upload and apply new firmware
6. Reboot router
🔧 Temporary Workarounds
Disable PPPoE Authentication
allSwitch to DHCP or static IP configuration instead of PPPoE
Restrict Web Interface Access
linuxLimit admin interface access to specific IP addresses only
iptables -A INPUT -p tcp --dport 80 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Replace vulnerable routers with updated models or different vendors
- Place routers behind dedicated firewalls with strict ingress filtering
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Status or Firmware Update sectionCheck Version:
curl -s http://router-ip/status.cgi | grep firmware || ssh admin@router 'cat /proc/version'Verify Fix Applied:
Verify firmware version is newer than affected versions listed above📡 Detection & Monitoring
Log Indicators:
- Unusual PPPoE configuration changes
- Multiple failed authentication attempts with special characters
- Commands containing shell metacharacters in web logs
Network Indicators:
- HTTP POST requests to PPPoE configuration endpoints with shell commands in parameters
- Outbound connections from router to unexpected destinations
SIEM Query:
source="router.log" AND ("pppoeUserName" OR "pppoePassword") AND ("|" OR ";" OR "`" OR "$")