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 |
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
Credit
This document was written by Garret Wassermann.
Other Information
- CVE IDs:CVE-2016-6559
- Date Public:06 Dec 2016
- Date First Published:06 Dec 2016
- Date Last Updated:06 Dec 2016
- Document Revision:31
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