BSD libc contains a buffer overflow 업데이트 권고

Overview

The BSD libc library is vulnerable to a classic buffer overflow.

Description

CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') - CVE-2016-6559 Improper bounds checking of the obuf variable in the link_ntoa() function in linkaddr.c may allow an attacker to read or write from memory. The full impact and severity depends on the method of exploit and how the library is used by applications. According to analysis by FreeBSD developers, it is very unlikely that applications exist that utilize link_ntoa() in an exploitable manner, and the CERT/CC is not aware of any proof of concept. The CVSS score below reflects a worst-case scenario in which an attacker may execute arbitrary code with root permissions.

Impact

The full impact and severity depends on the method of exploit and how the library is used by applications. An attacker may be able to execute arbitrary code, but CERT/CC is currently unaware of a proof of concept.

Solution

Apply an update BSD libc was updated to address this vulnerability. Affected users are encouraged to upgrade to the latest version of libc and/or the latest release of your operating system. In FreeBSD, the following patch levels (or later) contain a fix: 9.3-RELEASE-p51 10.1-RELEASE-p43 10.2-RELEASE-p26 10.3-RELEASE-p13 11.0-RELEASE-p4

Vendor Information (Learn More)

Vendor	Status	Date Notified	Date Updated
Apple	Affected	10 Oct 2016	16 Nov 2016
FreeBSD Project	Affected	21 Oct 2016	21 Nov 2016
DesktopBSD	Unknown	26 Oct 2016	26 Oct 2016
DragonFly BSD Project	Unknown	26 Oct 2016	26 Oct 2016
F5 Networks, Inc.	Unknown	26 Oct 2016	26 Oct 2016
Hardened BSD	Unknown	26 Oct 2016	26 Oct 2016
Juniper Networks	Unknown	26 Oct 2016	26 Oct 2016
NetBSD	Unknown	26 Oct 2016	26 Oct 2016
Nokia	Unknown	26 Oct 2016	26 Oct 2016
OpenBSD	Unknown	26 Oct 2016	26 Oct 2016
PC-BSD	Unknown	16 Nov 2016	16 Nov 2016
QNX Software Systems Inc.	Unknown	26 Oct 2016	26 Oct 2016
TrueOS	Unknown	16 Nov 2016	16 Nov 2016

CVSS Metrics (Learn More)

Group	Score	Vector
Base	9.3	AV:N/AC:M/Au:N/C:C/I:C/A:C
Temporal	9.3	E:ND/RL:ND/RC:ND
Environmental	7.0	CDP:ND/TD:M/CR:ND/IR:ND/AR:ND

References

• https://github.com/freebsd/freebsd/blob/386ddae58459341ec567604707805814a2128a57/lib/libc/net/linkaddr.c#L132
• http://cwe.mitre.org/data/definitions/120.html