CVE-2017-5495

All versions of Quagga, 0.93 through 1.1.0, are vulnerable to an unbounded
memory allocation in the telnet ‘vty’ CLI, leading to a Denial-of-Service
of Quagga daemons, or even the entire host. When Quagga daemons are
configured with their telnet CLI enabled, anyone who can connect to the TCP
ports can trigger this vulnerability, prior to authentication. Most
distributions restrict the Quagga telnet interface to local access only by
default. The Quagga telnet interface ‘vty’ input buffer grows
automatically, without bound, so long as a newline is not entered. This
allows an attacker to cause the Quagga daemon to allocate unbounded memory
by sending very long strings without a newline. Eventually the daemon is
terminated by the system, or the system itself runs out of memory. This is
fixed in Quagga 1.1.1 and Free Range Routing (FRR) Protocol Suite
2017-01-10.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=852454&gt;

Notes