Kernel use-after-free via the SNDCTL_DSP_SYNCSTART ioctl
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.8epss 0.1%
exploitation probability
0.1%top 97% of all CVEs
observed exploitation
nono source reports it
The implementation of this ioctl attempts to acquire locks on all channels in a sync group. If locking a channel would block, it releases the sync group list lock and sleeps. Upon reawakening, it is possible that the sync group structure is freed, but the implementation did not handle this possibility.
On a system with a multiple audio devices, 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