Security readout for executives and security teams
Plain-English summary
CVE-2020-3566 can let a remote unauthenticated attacker exhaust memory on Cisco IOS XR devices using crafted IGMP traffic against DVMRP handling. The business impact is network instability: routing processes may be disrupted, affecting availability of critical connectivity.
Executive priority
High priority for network teams. This is an availability risk to core routing infrastructure and appears in CISA's Known Exploited Vulnerabilities catalog. Confirm exposure and remediation status promptly.
Technical view
Cisco describes insufficient queue management for IGMP packets in the DVMRP feature of IOS XR. Exploitation can consume process memory and destabilize other processes, including interior and exterior routing protocols. CVSS 3.1 is 8.6 with network attack vector, low complexity, no privileges, and high availability impact.
Likely exposure
Exposure is most relevant to organizations running Cisco IOS XR Software with DVMRP/IGMP multicast handling reachable by untrusted or adjacent network traffic. The bundle does not provide affected release ranges or platform-specific exposure details.
Exploitation context
CISA KEV listing indicates known exploitation. The provided sources do not include exploit volume, affected targets, or detailed attacker tradecraft. Treat internet-facing or broadly reachable routing infrastructure as urgent until checked against Cisco guidance.
Researcher notes
The source bundle confirms CWE-400, CVSS 8.6, unauthenticated remote availability impact, and KEV status. It does not provide affected version granularity, exploit details, or final fixed-release mapping, so validation depends on Cisco advisory review.
Mitigation direction
- Check Cisco's advisory for affected releases, fixed releases, and workarounds.
- Prioritize vendor-supported IOS XR updates for confirmed affected devices.
- Inventory IOS XR routers using DVMRP or multicast features.
- Reduce untrusted reachability to affected multicast routing surfaces per Cisco guidance.
- Plan maintenance windows for routing infrastructure where updates are required.
Validation and detection
- Confirm IOS XR versions and feature configuration on all relevant routers.
- Compare device versions and platforms against Cisco's advisory.
- Review logs and telemetry for memory exhaustion or routing process instability.
- Verify whether CISA KEV tracking applies to your asset inventory.
- After remediation, monitor routing protocols and process memory stability.
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-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-3566 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
- Yes
- 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.
CISA KEV status
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
- 20200829 Cisco IOS XR Software DVMRP Memory Exhaustion VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566CVE reference · government-resource
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.