CVE-2020-3397 Cisco NX-OS Software Border Gateway Protocol Multicast VPN Denial of Service Vulnerability
Remote attackers can cause a denial of service on Cisco NX-OS devices by sending crafted BGP MVPN messages, requiring peer trust information.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-3397?
CVE-2020-3397 is a high-severity denial of service vulnerability in Cisco Nx-Os, published on 27 Aug 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.
Weakness: CWE-20
Which versions are affected by CVE-2020-3397?
It affects 1 product.
Products include Cisco Nx-Os.
How do I fix CVE-2020-3397?
No fix has been published for CVE-2020-3397 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-3397 being exploited?
There is no known exploitation of CVE-2020-3397 in the wild and no public exploit code.
Other vulnerabilities in Cisco Nx-Os
Sources
Also known as GHSA-5799-w2pr-v9hg.