Zero-day vulnerability in Cisco IOS XR

Resource exhaustion
CVE-2020-3566

Not patched

On August 28, 2020, the Cisco Product Security Incident Response Team (PSIRT) became aware of attempted exploitation of this vulnerability in the wild.

Vulnerability details

Advisory: SB2020082902 - Denial of service in Cisco IOS XR Software

Vulnerable component: Cisco IOS XR

CVE-ID: CVE-2020-3566

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:H/RL:U/RC:C

CWE-ID: CWE-400 - Resource exhaustion

Description:

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient queue management for Internet Group Management Protocol (IGMP) packets in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco┬аIOS XR Software. A remote attacker can trigger resource exhaustion by sending crafted IGMP┬а traffic to the affected device and perform a denial of service (DoS) attack.

Note: this vulnerability is being actively exploited in the wild.

External links:

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.