SB2019020607 - Multiple vulnerabilities in FreeBSD

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Buffer overflow (CVE-ID: CVE-2019-5596)

The vulnerability allows a local attacker to escalate privileges on the system.

The vulnerability exists in /dev/fd/due to the application attempts to handle the case where the receiving process does not provide a sufficiently large buffer for an incoming control message containing rights. A local attacker can cause the reference counter to wrap around and free the file structure and gain root privileges.

2) Information disclosure (CVE-ID: CVE-2019-5595)

The vulnerability allows a local attacker to gain access to potentially sensitive information.

The vulnerability exists due to the callee-save registers are used by kernel and for some of them (%r8, %r10, and for non-PTI configurations, %r9) the content is not sanitized before return from syscalls. A local attacker can gain unauthorized access to an address of some kernel data structure used in the syscall implementation.

Remediation

Install update from vendor's website.

References

• https://www.freebsd.org/security/advisories/FreeBSD-SA-19:02.fd.asc
• https://www.freebsd.org/security/advisories/FreeBSD-SA-19:01.syscall.asc