Security readout for executives and security teams
Plain-English summary
This affects Cisco IOS XR routers using BGP EVPN. A malformed EVPN BGP update can restart the BGP process, disrupting routing availability. Exploitation is remote but depends on a configured valid BGP peer or injection into an existing valid BGP connection.
Executive priority
Treat this as high priority for networks relying on Cisco IOS XR BGP EVPN. The main business risk is routing disruption, not data theft. Prioritization should focus on routers whose BGP EVPN peers could affect production availability.
Technical view
Cisco describes incorrect processing of BGP update messages containing crafted EVPN attributes. Successful processing can unexpectedly restart the BGP process, creating a denial-of-service condition. The CVSS 3.0 score is 8.6 with network attack vector and high availability impact.
Likely exposure
Exposure is most likely on Cisco IOS XR deployments where BGP EVPN is enabled and the device processes updates from configured peers. Internet exposure alone is not sufficient; Cisco notes BGP traffic is accepted only from explicitly defined peers.
Exploitation context
The source bundle does not indicate active exploitation, and KEV status is false. An attacker would need a valid configured BGP peer position or the ability to inject a malicious update into an existing valid BGP TCP connection.
Researcher notes
The evidence supports a peer-constrained remote DoS, not arbitrary unauthenticated Internet exploitation. The provided sources do not include exact vulnerable or fixed release data in the bundle, so validation should be anchored to Cisco’s advisory.
Mitigation direction
- Review Cisco’s advisory for affected IOS XR releases and vendor-provided fixed software guidance.
- Prioritize remediation on IOS XR routers running BGP EVPN with external or less-trusted peers.
- Audit configured BGP peers and remove stale, unauthorized, or unnecessary peer relationships.
- Monitor for unexpected BGP process restarts and routing instability until remediation is complete.
- Apply normal change control before updating core or provider-edge routing infrastructure.
Validation and detection
- Inventory Cisco IOS XR devices and identify where BGP EVPN is enabled.
- Compare running IOS XR versions against Cisco’s advisory and fixed-release guidance.
- Review BGP neighbor configuration for all EVPN-capable routers.
- Check operational logs for unexpected BGP restarts or EVPN-related update errors.
- Confirm monitoring alerts on BGP process restarts and route convergence impact.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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Open ATT&CK lookupCVE-2019-16019 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.6HighVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200122 Cisco IOS XR Software BGP EVPN Denial of Service VulnerabilitiesCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Resource Management Errors
Resource Management Errors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.