Security readout for executives and security teams
Plain-English summary
CVE-2019-15989 can make Cisco IOS XR routers unexpectedly restart their BGP process, disrupting routing availability. The attack is remote but constrained: the malicious BGP update must come from a configured peer or be injected into an existing valid BGP session.
Executive priority
Treat as high priority for network edge and service-provider routing environments. The business risk is loss of routing availability, not data theft, but outages can affect customer connectivity and dependent services.
Technical view
Cisco IOS XR Software incorrectly processes a BGP update containing a malformed attribute. Successful exploitation causes the BGP process to restart, producing a denial-of-service condition. CVSS is 8.6 with network attack vector, low complexity, no privileges, no user interaction, and high availability impact.
Likely exposure
Organizations using Cisco IOS XR Software with BGP enabled are potentially exposed. Practical exposure depends on configured BGP peers and whether an attacker can send through a valid peer relationship or existing valid TCP BGP session.
Exploitation context
The provided bundle does not show CISA KEV listing or active exploitation. The exploit path is constrained by Cisco's note that IOS XR accepts incoming BGP traffic only from explicitly defined peers.
Researcher notes
This is CWE-754 improper check for exceptional conditions. The bundle lists affected versions as unspecified, so version-level exposure and remediation must be validated against Cisco's advisory. Avoid assuming exploit availability or patches beyond vendor guidance.
Mitigation direction
- Check Cisco's advisory for affected releases, fixed software, and any listed workarounds.
- Inventory Cisco IOS XR devices running BGP and prioritize externally peered routers.
- Review BGP peer configuration and remove unauthorized or stale peers.
- Monitor for unexpected BGP process restarts and adjacency drops.
- Plan maintenance windows for vendor-recommended IOS XR updates.
Validation and detection
- Identify all Cisco IOS XR routers with BGP enabled.
- Compare each IOS XR version against Cisco's advisory guidance.
- Review configured BGP peers for business justification and ownership.
- Check logs for BGP process restarts around routing incidents.
- Verify alerting for BGP session resets and route instability.
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
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-754: Exact CWE lookup
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Open ATT&CK lookupCVE-2019-15989 mapping review
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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 Border Gateway Protocol Attribute Denial of Service VulnerabilityCVE 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.
Improper Check for Unusual or Exceptional Conditions
Improper Check for Unusual or Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.