SB2019020607 - Multiple vulnerabilities in FreeBSD

Description

This security bulletin contains information about 2 vulnerabilities.

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

CWE-ID: CWE-120 - Buffer overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear

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)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

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