#VU40394 Heap-based buffer overflow in FreeBSD - CVE-2016-1885

Vulnerability identifier: #VU40394

Vulnerability risk: Medium

CVSSv4.0: 5.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2016-1885

CWE-ID: CWE-122

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
FreeBSD
Operating systems & Components / Operating system

Vendor: FreeBSD Foundation

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Integer signedness error in the amd64_set_ldt function in sys/amd64/amd64/sys_machdep.c in FreeBSD 9.3 before p39, 10.1 before p31, and 10.2 before p14. A remote attacker can use an i386_set_ldt system call to trigger heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

FreeBSD: 9.3 - 10.2

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External links
https://packetstormsecurity.com/files/136276/FreeBSD-Kernel-amd64_set_ldt-Heap-Overflow.html
https://seclists.org/fulldisclosure/2016/Mar/56
https://seclists.org/fulldisclosure/2016/Mar/67
https://www.coresecurity.com/advisories/freebsd-kernel-amd64setldt-heap-overflow
https://www.securityfocus.com/archive/1/537812/100/0/threaded
https://www.securityfocus.com/archive/1/537813/100/0/threaded
https://www.securitytracker.com/id/1035309
https://security.FreeBSD.org/advisories/FreeBSD-SA-16:15.sysarch.asc
https://www.exploit-db.com/exploits/39570/

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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.