What it is
CVE-2020-3566 is an unauthenticated Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability. A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2020-3566
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
Cisco / Cisco IOS XR Software
- Severity
- CVSS 8.6 · High
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 3.7%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
Cisco / Cisco IOS XR Software.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to exhaust process memory of an affected device. The vulnerability is due to insufficient queue management for Internet Group Management Protocol (IGMP) packets. An attacker could exploit this vulnerability by sending crafted IGMP traffic to an affected device.
A successful exploit could allow the attacker to cause memory exhaustion, resulting in instability of other processes. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address this vulnerability.
- Published
- 29 Aug 2020
- Exploitation Reported
- 03 Nov 2021
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
edge
ios
cisa
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2020-3566
- 20200829 Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability tools.cisco.com · Vendor Advisory https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory...
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
CISA
Independent exploitation attestation added to the KEV Intelligence record.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2021-11-03 00:00 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
8.6
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
3.7%
Weaknesses
Timeline
From disclosure to observed exploitation
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2020-3566
Free JSON includes basic KEV fields{
"cve_id": "CVE-2020-3566",
"confidence": "Confirmed",
"cvss_score": 8.6,
"cvss_estimated": false,
"epss_score": 0.03702,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.