Advisory Details

August 6th, 2020

FreeBSD Kernel sendmsg System Call Time-Of-Check Time-Of-Use Privilege Escalation Vulnerability

ZDI-20-949
ZDI-CAN-11543

CVE ID CVE-2020-7460
CVSS SCORE 8.8, (AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
AFFECTED VENDORS FreeBSD
AFFECTED PRODUCTS Kernel
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of FreeBSD Kernel. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the handling of arguments to the sendmsg system call. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the kernel.

ADDITIONAL DETAILS FreeBSD has issued an update to correct this vulnerability. More details can be found at:
https://www.freebsd.org/security/advisories/FreeBSD-SA-20:23.sendmsg.asc
DISCLOSURE TIMELINE
  • 2020-07-24 - Vulnerability reported to vendor
  • 2020-08-06 - Coordinated public release of advisory
CREDIT m00nbsd
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