CVE-2019-16021 Cisco IOS XR Software BGP EVPN Denial of Service Vulnerabilities
Remote attackers can cause a denial of service by sending malformed BGP EVPN update messages to Cisco IOS XR devices.
- 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-2019-16021?
CVE-2019-16021 is a high-severity denial of service vulnerability in Cisco Ios Xr, published on 23 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Multiple vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes to be processed by an affected system. A successful exploit could allow the attacker to cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit these vulnerabilities, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.
Weakness: CWE-399
Which versions are affected by CVE-2019-16021?
It affects 1 product.
Products include Cisco Ios Xr.
How do I fix CVE-2019-16021?
No fix has been published for CVE-2019-16021 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-2019-16021 being exploited?
There is no known exploitation of CVE-2019-16021 in the wild and no public exploit code.
Other vulnerabilities in Cisco Ios Xr
- CVE-2020-3118 Cisco IOS XR Software Discovery Protocol Format String
- CVE-2020-3569 Cisco IOS XR Software DVMRP Memory Exhaustion
- CVE-2020-3566 Cisco IOS XR Software DVMRP Memory Exhaustion
- CVE-2010-3035 Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service
- CVE-2022-20821 Cisco IOS XR Open Port
Sources
Also known as GHSA-w626-fpjc-h33x.