APP: Quagga VTY Interface Denial of Service
This signature detects attempts to exploit a known vulnerability in Quagga. Successful exploitation would cause the target Quagga daemon to allocate excessive memory and crash, resulting in denial-of-service conditions.
Extended Description
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 Products
Quagga quagga
References
CVE: CVE-2017-5495
Short Name
APP:MISC:QUAGGA-VTY-DOS
Severity
Major
Recommended
True
Recommended Action
Drop
Category
APP
Keywords
CVE-2017-5495 Denial Interface Quagga Service VTY of
Release Date
03/16/2017
Supported Platforms
srx-branch-12.3
srx-19.3
srx-branch-19.3
vsrx3bsd-19.2
srx-branch-19.4
vsrx-19.4
mx-12.3
mx-19.4
vmx-19.4
mx-19.3
vsrx3bsd-19.4
srx-19.4
vsrx-12.3
vmx-19.3
vsrx-19.2
srx-12.3
Sigpack Version
3415
Port
TCP/2601-2606
False Positive
Unknown
Vendors
Quagga
CVSS Score
7.8