CVE-2020-29394
📋 TL;DR
This CVE describes a buffer overflow vulnerability in the dlt-daemon component of GENIVI Diagnostic Log and Trace. The flaw allows arbitrary code execution via a misused fscanf function that lacks proper input validation. Systems using dlt-daemon versions through 2.18.5 are affected.
💻 Affected Systems
- GENIVI Diagnostic Log and Trace (dlt-daemon)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote attackers could execute arbitrary code with the privileges of the dlt-daemon process, potentially leading to full system compromise.
Likely Case
Local or network-adjacent attackers could crash the service or execute limited code, disrupting logging functionality.
If Mitigated
With proper network segmentation and least privilege, impact is limited to service disruption without system compromise.
🎯 Exploit Status
Exploitation requires sending specially crafted input to the dlt-daemon service. No public exploit code has been identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.18.6 and later
Vendor Advisory: https://github.com/GENIVI/dlt-daemon/issues/274
Restart Required: Yes
Instructions:
1. Update dlt-daemon to version 2.18.6 or later. 2. Restart the dlt-daemon service. 3. Verify the patch is applied by checking the version.
🔧 Temporary Workarounds
Disable dlt-daemon if not needed
linuxStop and disable the dlt-daemon service if diagnostic logging is not required.
sudo systemctl stop dlt-daemon
sudo systemctl disable dlt-daemon
🧯 If You Can't Patch
- Implement strict network segmentation to isolate systems using dlt-daemon
- Apply strict input validation and filtering for dlt-daemon inputs
🔍 How to Verify
Check if Vulnerable:
Check dlt-daemon version with 'dlt-daemon --version' or 'dpkg -l | grep dlt-daemon'Check Version:
dlt-daemon --versionVerify Fix Applied:
Verify version is 2.18.6 or higher and check for any crash logs in systemd journal📡 Detection & Monitoring
Log Indicators:
- dlt-daemon crash logs
- segmentation fault errors in system logs
- unusual process termination
Network Indicators:
- Unusual network traffic to dlt-daemon port (default 3490)
SIEM Query:
process_name:"dlt-daemon" AND (event_type:crash OR exit_code:139)🔗 References
- https://github.com/GENIVI/dlt-daemon/issues/274
- https://github.com/GENIVI/dlt-daemon/pull/275
- https://github.com/GENIVI/dlt-daemon/pull/288
- https://lists.debian.org/debian-lts-announce/2022/12/msg00016.html
- https://github.com/GENIVI/dlt-daemon/issues/274
- https://github.com/GENIVI/dlt-daemon/pull/275
- https://github.com/GENIVI/dlt-daemon/pull/288
- https://lists.debian.org/debian-lts-announce/2022/12/msg00016.html
