CVE-2023-3494

Summary

The fwctl driver implements a state machine which is executed when a bhyve guest accesses certain x86 I/O ports. The interface lets the guest copy a string into a buffer resident in the bhyve process' memory. A bug in the state machine implementation can result in a buffer overflowing when copying this string. Malicious, privileged software running in a guest VM can exploit the buffer overflow to achieve code execution on the host in the bhyve userspace process, which typically runs as root, mitigated by the capabilities assigned through the Capsicum sandbox available to the bhyve process.

Affected Software

VendorProductVersion RangeStatus
FreeBSDFreeBSD13.2-RELEASE < 13.2-RELEASE-p2affected
FreeBSDFreeBSD13.1-RELEASE < 13.1-RELEASE-p9affected

Weaknesses

  • CWE-120: CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References