IPSec VPN authentication bypass in several Cisco RV routers

1) Incorrect implementation of authentication algorithm

EUVDB-ID: #VU67072

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-20923

CWE-ID: CWE-303 - Incorrect Implementation of Authentication Algorithm

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in the password validation algorithm in IPSec VPN Server authentication functionality. A remote non-authenticated attacker can bypass authentication process and gain unauthorized access to the IPSec VPN network.

Mitigation

The affected routers are no longer supported by the vendor and Cisco will not release any security patches to address this vulnerability. It is recommended to replace the affected devices.

Vulnerable software versions

RV110W Wireless-N VPN Firewall: All versions

Cisco Small Business RV130 Series VPN Routers: All versions

RV130W Wireless-N Multifunction VPN Router: All versions

RV215W Wireless-N VPN Router: All versions

CPE2.3

• cpe:2.3:h:cisco_systems:rv110w_wireless-n_vpn_firewall:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_small_business_rv130_series_vpn_routers:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:rv130w_wireless-n_multifunction_vpn_router:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:rv215w_wireless-n_vpn_router:*:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-rv-vpnbypass-Cpheup9O
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwc57664
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwc57666
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwc57640

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.