CyberSecBulletin
CVE-2022-20923NVD status: Modified

Cisco Small Business RV Series Router Firmware: Improper Authentication

Published Updated By the CyberSecBulletin desk

CVE-2022-20923 is a critical-severity improper authentication 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. There is no confirmed exploitation so far. EPSS estimates a 0.96% chance of exploitation within 30 days, higher than 62% 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 tools.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 FirmwareNot specified in the recordNot stated
CiscoRv110w Firmware1.0.3.55; 1.2.2.8; 1.3.1.7Not stated
CiscoRv130 Firmware1.0.3.55; 1.2.2.8; 1.3.1.7Not stated
CiscoRv130w Firmware1.0.3.55; 1.2.2.8; 1.3.1.7Not stated
CiscoRv215w Firmware1.0.3.55; 1.2.2.8; 1.3.1.7Not 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 3.14.0MediumCNA (cisco.com)
CVSS 3.19.8CriticalNVD

Official description

A vulnerability in the IPSec VPN Server authentication functionality of Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers could allow an unauthenticated, remote attacker to bypass authentication controls and access the IPSec VPN network. This vulnerability is due to the improper implementation of the password validation algorithm. An attacker could exploit this vulnerability by logging in to the VPN from an affected device with crafted credentials. A successful exploit could allow the attacker to bypass authentication and access the IPSec VPN network. The attacker may obtain privileges that are the same level as an administrative user, depending on the crafted credentials that are used. Cisco has not released software updates that address this vulnerability.

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

The underlying weakness: Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

How developers prevent this class of flaw

  • Use an authentication framework or library such as the OWASP ESAPI Authentication feature.

More Improper Authentication vulnerabilities (CWE-287)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  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 Improper Authentication vulnerabilities

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