Use-after-free bug in the IPV6_MSFILTER socket option handler
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.8epss 0.2%
exploitation probability
0.2%top 95% of all CVEs
observed exploitation
nono source reports it
The kernel handler for IPV6_MSFILTER dropped a serializing lock in order to copy the source-filter list from userspace, then reacquired the lock. During this window another thread could free the multicast filter structure, leaving the handler with a stale pointer to freed memory.
An unprivileged local user can exploit this use-after-free to escalate privileges.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
FreeBSD · FreeBSD