CVE-2019-16021
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.
EPSS 1.31% · 80.2th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| cisco | ios_xr | 6.6.1, 6.6.25, 7.0.1 |
| Cisco | Cisco IOS XR Software | n/a |
Exploit Intelligence
Timeline
- Sep 23, 2020 CVE Published
- Apr 14, 2021 EPSS Score
- Jun 23, 2021 EPSS Score
- Oct 26, 2021 EPSS Score
- Dec 27, 2021 EPSS Score
- Jan 6, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- Apr 1, 2022 EPSS Score
- May 1, 2022 EPSS Score
- Jul 3, 2022 EPSS Score
- Sep 4, 2022 EPSS Score
- Jan 8, 2023 EPSS Score
References
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-telepresence-path-tr-wdrnYEZZ advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-fmc-auth advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-evpn advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-cred-EVGSF259 advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-routes advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-sdwan-priv-esc advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-on-prem-dos advisory
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200122-ios-xr-dos advisory
- https://nvd.nist.gov/vuln/detail/CVE-2019-16021 advisory