CVE-2024-7538
📋 TL;DR
This vulnerability in oFono allows local attackers to execute arbitrary code with root privileges by exploiting a stack-based buffer overflow in AT command response parsing. It affects systems running vulnerable versions of oFono where an attacker has already obtained code execution capability on the target modem. The vulnerability stems from insufficient length validation of user-supplied data before copying to a stack buffer.
💻 Affected Systems
- oFono
📦 What is this software?
Ofono by Ofono Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with root-level code execution, allowing complete control over the affected device and potential lateral movement to connected systems.
Likely Case
Local privilege escalation from a lower-privileged user to root, enabling persistence, data theft, and further system manipulation.
If Mitigated
Limited impact due to proper access controls and isolation, with only denial of service or minor disruption if exploitation attempts are detected and blocked.
🎯 Exploit Status
Exploitation requires local access and initial code execution capability on the target modem. The buffer overflow must be carefully crafted to achieve code execution.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in available references, but patch exists per ZDI advisory
Vendor Advisory: https://www.zerodayinitiative.com/advisories/ZDI-24-1078/
Restart Required: Yes
Instructions:
1. Check oFono project for latest version. 2. Update oFono to patched version. 3. Restart oFono service. 4. Verify the fix is applied.
🔧 Temporary Workarounds
Disable AT command processing
linuxIf AT command functionality is not required, disable it to prevent exploitation
Modify oFono configuration to disable AT command support
Restart oFono service after configuration change
Implement strict access controls
linuxLimit local access to systems running oFono and modem interfaces
Configure firewall rules to restrict modem interface access
Implement least privilege for local users
🧯 If You Can't Patch
- Isolate affected systems from critical networks and implement network segmentation
- Implement strict monitoring and anomaly detection for oFono processes and AT command activity
🔍 How to Verify
Check if Vulnerable:
Check oFono version and compare against patched versions. Review system logs for AT command processing errors or crashes.Check Version:
ofonod --version or check package manager (e.g., dpkg -l | grep ofono)Verify Fix Applied:
Verify oFono version is updated beyond vulnerable versions. Test AT command functionality to ensure it works without crashes.📡 Detection & Monitoring
Log Indicators:
- oFono process crashes
- AT command parsing errors
- Stack overflow messages in system logs
Network Indicators:
- Unusual AT command traffic to modem interfaces
- Multiple failed AT command attempts
SIEM Query:
Process:ofonod AND (EventID:1000 OR "stack overflow" OR "buffer overflow")