CVE-2016-6559: bsd libc library Classic Buffer Overflow

Vulnerability summary

CVE-2016-6559 is a critical (CVSS 9.8) Classic Buffer Overflow vulnerability in bsd libc library. EPSS estimates a 3.65% chance of exploitation in the next 30 days, higher than 89.4% of scored vulnerabilities.

Timeline

1. 13-07-2018
   PublishedVulnerability first disclosed.
2. 06-08-2024
   Last modifiedVulnerability information updated.

Description

Improper bounds checking of the obuf variable in the link_ntoa() function in linkaddr.c of the BSD libc library 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. A blog post describes the functionality of link_ntoa() and points out that none of the base utilities use this function in an exploitable manner. For more information, please see FreeBSD Security Advisory SA-16:37.

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.