CVE-2024-42416
📋 TL;DR
This vulnerability allows arbitrary write to kernel memory in FreeBSD's bhyve hypervisor due to insufficient validation in the ctl_report_supported_opcodes function. Malicious software in a guest VM can exploit this to achieve code execution on the host as root, though constrained by Capsicum sandbox. Affects FreeBSD systems using bhyve with virtio_scsi.
💻 Affected Systems
- FreeBSD
- NetApp products using affected FreeBSD versions
📦 What is this software?
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Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
Freebsd by Freebsd
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution on the host system as root, potentially leading to full host compromise and lateral movement.
Likely Case
Privilege escalation from guest VM to host bhyve process, allowing host file system access and further exploitation within sandbox constraints.
If Mitigated
Limited impact due to Capsicum sandbox restrictions, preventing full system compromise but still allowing data exfiltration and limited host access.
🎯 Exploit Status
Exploitation requires access to guest VM or iSCSI initiator. Capsicum sandbox limits impact but root code execution is possible.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: FreeBSD 13.2-RELEASE p6, 13.3-RELEASE p2, 14.0-RELEASE p5, 14.1-RELEASE p1
Vendor Advisory: https://security.freebsd.org/advisories/FreeBSD-SA-24:11.ctl.asc
Restart Required: Yes
Instructions:
1. Update FreeBSD using freebsd-update fetch && freebsd-update install
2. Rebuild kernel if using custom kernel
3. Restart affected bhyve instances and host if necessary
🔧 Temporary Workarounds
Disable virtio_scsi in bhyve
allRemove or disable virtio_scsi device from bhyve VM configurations
Edit bhyve configuration to remove '-s' options with virtio-scsi
Network segmentation for iSCSI
allIsolate iSCSI traffic to trusted networks only
🧯 If You Can't Patch
- Disable bhyve hypervisor if not required
- Implement strict network controls for iSCSI traffic and guest VM network access
🔍 How to Verify
Check if Vulnerable:
Check FreeBSD version with 'uname -a' and compare against affected versions. Verify bhyve usage and virtio_scsi configuration.Check Version:
uname -aVerify Fix Applied:
Confirm FreeBSD version is patched with 'uname -a'. Check that no bhyve instances are using vulnerable configurations.📡 Detection & Monitoring
Log Indicators:
- Unexpected bhyve process crashes
- Kernel panic messages related to ctl or SCSI
- Unusual iSCSI connection attempts
Network Indicators:
- Abnormal iSCSI traffic patterns
- Unexpected connections to iSCSI ports from untrusted sources
SIEM Query:
process_name:"bhyve" AND (event_type:"crash" OR event_type:"privilege_escalation")