CyberSecBulletin
CVE-2023-20025NVD status: Analyzed

Cisco Small Business RV Series Router Firmware: Authentication Bypass by Spoofing

Published Updated By the CyberSecBulletin desk

CVE-2023-20025 is a critical-severity authentication bypass by spoofing vulnerability in Cisco Small Business RV Series Router Firmware from Cisco, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco Small Business RV Series Router Firmware versions: 2.0.0.19-tm; 2.0.2.01-tm; 1.3.12.19-tm, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.64% chance of exploitation within 30 days, higher than 77% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Cisco Small Business RV Series Router Firmware you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Small Business RV Series Router Firmware2.0.0.19-tm; 2.0.2.01-tm; 1.3.12.19-tm; 1.3.12.6-tm; 1.3.13.02-tm; 1.3.9.8-tm; 4.0.0.7; 4.0.2.08-tm; and 16 more rangesNot stated
CiscoRv016 FirmwareNot specified in the recordNot stated
CiscoRv042 FirmwareNot specified in the recordNot stated
CiscoRv042g FirmwareNot specified in the recordNot stated
CiscoRv082 FirmwareNot specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.0CriticalCNA (cisco.com)
CVSS 3.19.8CriticalNVD

Official description

A vulnerability in the web-based management interface of Cisco Small Business RV016, RV042, RV042G, and RV082 Routers could allow an unauthenticated, remote attacker to bypass authentication on an affected device. This vulnerability is due to improper validation of user input within incoming HTTP packets. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web-based management interface. A successful exploit could allow the attacker to bypass authentication and gain root access on the underlying operating system.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Authentication Bypass by Spoofing

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

More Authentication Bypass by Spoofing vulnerabilities (CWE-290)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco Small Business RV Series Router Firmware

All Cisco Small Business RV Series Router Firmware vulnerabilities

Recent Authentication Bypass by Spoofing vulnerabilities

Spotted an error? Tell us.