CVE-2024-39207
📋 TL;DR
CVE-2024-39207 is a buffer overflow vulnerability in lua-shmem v1.0-1's shmem_write function that allows attackers to write beyond allocated memory boundaries. This affects systems using the vulnerable lua-shmem library, potentially leading to arbitrary code execution or denial of service. The vulnerability is exploitable by any process that can interact with the shared memory interface.
💻 Affected Systems
- lua-shmem
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the process using lua-shmem, potentially leading to complete system compromise.
Likely Case
Denial of service through application crashes or memory corruption, potentially disrupting dependent services.
If Mitigated
Limited impact if proper memory protection mechanisms (ASLR, DEP) are enabled and the process runs with minimal privileges.
🎯 Exploit Status
Exploitation requires the attacker to have the ability to write to shared memory via the shmem_write function. Public proof-of-concept code is available in the referenced GitHub gist.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check upstream repository for patched versions (likely v1.0-2 or higher)
Vendor Advisory: https://github.com/yanggao017/vuln/blob/main/lua-shmem.md
Restart Required: Yes
Instructions:
1. Check current lua-shmem version. 2. Update to the latest patched version from the official repository. 3. Restart any services or applications using lua-shmem.
🔧 Temporary Workarounds
Disable or remove lua-shmem
linuxIf lua-shmem is not essential, disable or uninstall it to eliminate the vulnerability.
sudo apt remove lua-shmem
sudo yum remove lua-shmem
Restrict shared memory access
linuxUse operating system controls to restrict which processes can access the shared memory segment used by lua-shmem.
chmod 600 /dev/shm/lua-shmem-*
setfacl -m u:appuser:rw /dev/shm/lua-shmem-*
🧯 If You Can't Patch
- Implement strict network segmentation to isolate systems using lua-shmem from untrusted networks.
- Run processes using lua-shmem with minimal privileges (non-root users, restricted capabilities).
🔍 How to Verify
Check if Vulnerable:
Check the installed version of lua-shmem: `dpkg -l | grep lua-shmem` or `rpm -qa | grep lua-shmem`. If version is v1.0-1, the system is vulnerable.Check Version:
dpkg -l | grep lua-shmem || rpm -qa | grep lua-shmem || find /usr -name '*lua-shmem*' -type fVerify Fix Applied:
After updating, verify the version is no longer v1.0-1 and test the application functionality that uses lua-shmem.📡 Detection & Monitoring
Log Indicators:
- Application crashes or segmentation faults in processes using lua-shmem
- Unusual memory access patterns in system logs
Network Indicators:
- Unusual inter-process communication attempts targeting shared memory segments
SIEM Query:
source="application.log" AND ("segmentation fault" OR "buffer overflow") AND "lua-shmem"