VDB-93971 · CVE-2016-6559 · BID 94694

GNU C Library 9.3/10.1/10.2/10.3/11.0 on macOS link_ntoa memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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A vulnerability, which was classified as critical, has been found in GNU C Library 9.3/10.1/10.2/10.3/11.0 on macOS (Software Library). This issue affects the function link_ntoa. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The software performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability.

The weakness was released 12/06/2016 as FreeBSD-SA-16:37.libc as confirmed security advisory (Website). It is possible to read the advisory at security.FreeBSD.org. The identification of this vulnerability is CVE-2016-6559. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The advisory points out:

A specially crafted argument can trigger a static buffer overflow in the library, with possibility to rewrite following static buffers that belong to other library functions.

The vulnerability scanner Nessus provides a plugin with the ID 95585 (FreeBSD : FreeBSD -- link_ntoa(3) buffer overflow (0282269d-bbee-11e6-b1cf-14dae9d210b8)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD Local Security Checks.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at SecurityTracker (ID 1037398) and Tenable (95585).






  • open-source

CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 8.5
VulDB Meta Temp Score: 8.4

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
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NVD Base Score: 9.8
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Class: Memory corruption
CWE: CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

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Nessus ID: 95585
Nessus Name: FreeBSD : FreeBSD -- link_ntoa(3) buffer overflow (0282269d-bbee-11e6-b1cf-14dae9d210b8)
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Threat Intelligenceinfo

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Recommended: Patch
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08/03/2016 🔍
12/06/2016 +125 days 🔍
12/06/2016 +0 days 🔍
12/06/2016 +0 days 🔍
12/07/2016 +1 days 🔍
07/13/2018 +582 days 🔍
10/05/2022 +1545 days 🔍


Vendor: gnu.org

Advisory: FreeBSD-SA-16:37.libc
Status: Confirmed

CVE: CVE-2016-6559 (🔍)
SecurityTracker: 1037398 - libc link_ntoa() Buffer Overflow Lets Users Execute Arbitrary Code
SecurityFocus: 94694


Created: 12/07/2016 10:38 AM
Updated: 10/05/2022 08:15 AM
Changes: 12/07/2016 10:38 AM (46), 02/15/2019 01:53 PM (16), 10/05/2022 08:06 AM (3), 10/05/2022 08:10 AM (11), 10/05/2022 08:15 AM (1)
Complete: 🔍


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