CVE-2017-5495: Buffer Overflow
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
quaggato a version that resolves this vulnerability.Fixed in 1.1.1 - Compensating control
Restrict the Quagga telnet interface (vty CLI) TCP access to local access only by default, since this vulnerability can be triggered prior to authentication by anyone who can connect to the telnet TCP ports.
Event History
Frequently Asked Questions
What is the severity of CVE-2017-5495?
CVE-2017-5495 has a severity score of 7.5, indicating a high level of risk.
How do I fix CVE-2017-5495?
To fix CVE-2017-5495, upgrade Quagga to a version later than 1.1.0 where the vulnerability is resolved.
What type of vulnerability is CVE-2017-5495?
CVE-2017-5495 is classified as an unbounded memory allocation vulnerability.
What impact does CVE-2017-5495 have on my system?
CVE-2017-5495 can lead to a Denial-of-Service affecting Quagga daemons or potentially the entire host.
Which versions of Quagga are affected by CVE-2017-5495?
All versions of Quagga from 0.93 to 1.1.0 are affected by CVE-2017-5495.