This module exploits a race and use-after-free vulnerability in the FreeBSD kernel IPv6 socket handling. A missing synchronization lock in the `IPV6_2292PKTOPTIONS` option handling in `setsockopt` permits racing `ip6_setpktopt` access to a freed `ip6_pktopts` struct. This exploit overwrites the `ip6po_pktinfo` pointer of a `ip6_pktopts` struct in freed memory to achieve arbitrary kernel read/write. This module has been tested successfully on: FreeBSD 9.0-RELEASE #0 (amd64); FreeBSD 9.1-RELEASE #0 r243825 (amd64); FreeBSD 9.2-RELEASE #0 r255898 (amd64); FreeBSD 9.3-RELEASE #0 r268512 (amd64); FreeBSD 12.0-RELEASE r341666 (amd64); and FreeBSD 12.1-RELEASE r354233 (amd64).
BSD
x64
To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':
msf > use exploit/freebsd/local/ip6_setpktopt_uaf_priv_esc
msf exploit(ip6_setpktopt_uaf_priv_esc) > show targets
...targets...
msf exploit(ip6_setpktopt_uaf_priv_esc) > set TARGET < target-id >
msf exploit(ip6_setpktopt_uaf_priv_esc) > show options
...show and set options...
msf exploit(ip6_setpktopt_uaf_priv_esc) > exploit
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– Jim O’Gorman | President, Offensive Security