Security readout for executives and security teams
Plain-English summary
CVE-2021-1288 affects Cisco IOS XR Software and can let a remote unauthenticated attacker cause a denial of service on an affected device. The business risk is network availability: impacted routers or infrastructure devices could become unavailable if exposed to malicious traffic.
Executive priority
Prioritize based on the role of IOS XR devices in core routing, edge connectivity, or service availability. A successful attack affects uptime rather than confidentiality or integrity, but outages on routing infrastructure can create broad business disruption.
Technical view
Cisco describes vulnerabilities in IOS XR ingress packet processing associated with the Enf Broker DoS advisory. CVSS 3.1 is 8.6 with network attack vector, low complexity, no privileges, no user interaction, changed scope, and high availability impact only.
Likely exposure
Exposure is most likely in environments running Cisco IOS XR Software on network infrastructure. The provided sources do not list specific affected versions, so teams must compare their IOS XR inventory against Cisco’s advisory.
Exploitation context
The bundle does not show CISA KEV inclusion or cited evidence of active exploitation. Treat this as a high-impact availability issue, not a confirmed exploited vulnerability based on the provided sources.
Researcher notes
Evidence supports unauthenticated remote DoS risk against affected Cisco IOS XR Software through ingress packet processing. The provided bundle lacks affected version ranges, exploit details, and concrete mitigation text, so validation should rely on Cisco’s advisory and local asset inventory.
Mitigation direction
- Review Cisco’s advisory for affected releases and vendor remediation guidance.
- Inventory all Cisco IOS XR Software deployments and versions.
- Prioritize remediation for internet-facing or business-critical network infrastructure.
- Reduce unnecessary network reachability to affected infrastructure where feasible.
- Monitor affected devices for availability degradation and abnormal packet-processing failures.
Validation and detection
- Confirm whether any deployed device runs Cisco IOS XR Software.
- Compare IOS XR versions against Cisco’s advisory guidance.
- Verify remediation status for each affected device in asset records.
- Check monitoring for recent unexplained device resets or DoS-like availability events.
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-399: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-1288 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 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/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:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210203 Cisco IOS XR Software Enf Broker 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.
Resource Management Errors
Resource Management Errors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.