Cisco IOS/IOS XE/Meraki/NX-OS/Small Business Switch IPv6 RA Guard/ARP Inspection authentication spoofing
|CVSS Meta Temp Score|
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
|Current Exploit Price (≈)|
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
|CTI Interest Score|
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
A vulnerability was found in Cisco IOS, IOS XE, Meraki, NX-OS and Small Business Switch (Router Operating System). It has been rated as critical. Affected by this issue is an unknown code of the component IPv6 RA Guard/ARP Inspection. The manipulation with an unknown input leads to a authentication spoofing vulnerability. Using CWE to declare the problem leads to CWE-290. This attack-focused weakness is caused by improperly implemented authentication schemes that are subject to spoofing attacks. Impacted is confidentiality, integrity, and availability. CVE summarizes:
Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.
The weakness was shared 09/28/2022 as cisco-sa-VU855201-J3z8CKTX. The advisory is available at tools.cisco.com. This vulnerability is handled as CVE-2021-27853 since 03/01/2021. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/24/2022).
Upgrading eliminates this vulnerability.
CVSSv3VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4
VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍
NVD Base Score: 4.7
NVD Vector: 🔒
VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
ExploitingClass: Authentication spoofing
CWE: CWE-290 / CWE-287
Status: Not defined
EPSS Score: 🔒
EPSS Percentile: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒
Threat IntelligenceInterest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍
0-Day Time: 🔒
Timeline03/01/2021 CVE reserved
09/28/2022 +575 days Advisory disclosed
09/28/2022 +0 days VulDB entry created
10/24/2022 +26 days VulDB last update
CVE: CVE-2021-27853 (🔒)
scip Labs: https://www.scip.ch/en/?labs.20150108
EntryCreated: 09/28/2022 07:03 AM
Updated: 10/24/2022 03:29 PM
Changes: 09/28/2022 07:03 AM (40), 10/24/2022 03:29 PM (11)
Want to stay up to date on a daily basis?
Enable the mail alert feature now!