Known exploited vulnerability
CVE-2020-3566
The short answer
CVE-2020-3566 affects Cisco Cisco IOS XR Software and is rated high (CVSS 8.6). CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: attackers are using it, so patch it first.
What it is
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.
Severity
8.6 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Exploited (CISA KEV)
Yes, since Nov 3, 2021
Federal due date May 3, 2022
EPSS, next 30 days
3.7%
Higher than 90% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
What CISA says to do
Apply updates per vendor instructions.
Affected products
Cisco IOS XR Software. NVD's record lists the exact affected versions.
References
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz Vendor Advisory
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566 US Government Resource
Questions
Is CVE-2020-3566 being exploited?
Yes. CISA added CVE-2020-3566 to its Known Exploited Vulnerabilities catalog on 2021-11-03, with a federal remediation due date of 2022-05-03.
How do I fix CVE-2020-3566?
CISA's required action: Apply updates per vendor instructions.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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