Multiple vulnerabilities in FreeBSD

Published: 2019-02-06 | Updated: 2019-02-06

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2019-5596 CVE-2019-5595
CWE-ID	CWE-120 CWE-200
Exploitation vector	Local
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software Subscribe	FreeBSD Operating systems & Components / Operating system
Vendor	FreeBSD Foundation

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Buffer overflow

EUVDB-ID: #VU17378

Risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-5596

CWE-ID: CWE-120 - Buffer overflow

Exploit availability: Yes

Description

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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

FreeBSD: 12.0

External links

http://www.freebsd.org/security/advisories/FreeBSD-SA-19:02.fd.asc

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Information disclosure

EUVDB-ID: #VU17379

Risk: Low

CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-5595

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

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.