CVE-2020-3566
Actively exploited. CVE-2020-3566 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03) — exploitation has been observed in the wild, and US federal agencies are required to remediate it under BOD 22-01. Treat patching as urgent.
Cisco IOS XR Distance Vector Multicast Routing Protocol (DVMRP) incorrectly handles Internet Group Management Protocol (IGMP) packets. Exploitation could allow an unauthenticated, remote attacker to immediately crash the IGMP process or make it consume available memory and eventually crash.
CSIRTS triage
- What
- Cisco IOS XR Distance Vector Multicast Routing Protocol (DVMRP) incorrectly handles Internet Group Management Protocol (IGMP) packets, potentially leading to crashes.
- Who is affected
- Users of Cisco IOS XR Software are affected by this vulnerability.
- Urgency
- Remediation is urgent due to the critical nature of the vulnerability and its exploitation status.
- Action
- Users should update to the latest version of IOS XR Software.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Exploitation confirmedAlready exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 88% of all EPSS-scored CVEs.
Advisory coverage (1)
- criticalexploitedCVE-2020-3566: Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilitycisa-kev · 2021-11-03
External references
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