A heap-based buffer overflow in c-ares might allow remote attackers to cause a Denial of Service condition.
|Package||net-dns/c-ares on all architectures|
|Affected versions||< 1.12.0|
|Unaffected versions||>= 1.12.0|
c-ares is a C library for asynchronous DNS requests (including name resolves).
A hostname with an escaped trailing dot (such as “hello\.”) would have its size calculated incorrectly leading to a single byte written beyond the end of a buffer on the heap.
A remote attacker, able to provide a specially crafted hostname to an application using c-ares, could potentially cause a Denial of Service condition.
There is no known workaround at this time.
All c-ares users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=net-dns/c-ares-1.12.0"
January 11, 2017
January 11, 2017: 1