CVE-2022-20699, CVE-2022-20700, CVE-2022-20708: Critical Flaws in Cisco Small Business RV Series Routers

Cisco patches 15 flaws in Cisco Small Business RV Series Routers, including three with critical 10.0 CVSSv3 scores.

Background

On February 2, Cisco published an advisory for 15 vulnerabilities in its Small Business RV Series Routers. Three of the 15 vulnerabilities listed in the advisory
received a CVSSv3 score of 10.0, the highest possible rating.

Analysis

CVE-2022-20699 is a remote code execution (RCE) vulnerability in the Cisco RV340, RV340W, RV345 and RV345P Dual WAN
Gigabit Routers. According to Cisco, the flaws exist due to an insufficient boundary check within the Secure Socket
Layer Virtual Private Network (SSL VPN) module of these devices. A remote, unauthenticated attacker could exploit
this flaw by sending a specially crafted HTTP request to a vulnerable device that is “acting as an SSL VPN Gateway.”
Successful exploitation would grant an attacker arbitrary code execution on the device with root privileges.

CVE-2022-20700, CVE-2022-20701, CVE-2022-20702 are elevation of privilege vulnerabilities in the RV160, RV160W,
RV260, RV260P, RV260W, RV340, RV340W, RV345 and RV345P routers. According to Cisco, these vulnerabilities reside in
the web-based management interface of its Cisco Small Business RV Series Routers. The most severe of these three
flaws is CVE-2022-20700. A remote, unauthenticated attacker could exploit this vulnerability by “submitting specific
commands” to a vulnerable device. Successful exploitation would elevate the attacker’s privileges, allowing them to
execute arbitrary commands as root.

CVE-2022-20707, CVE-2022-20708 and CVE-2022-20749 are RCE vulnerabilities in the Cisco RV340, RV340W, RV345 and
RV345P Dual WAN Gigabit Routers. The most severe of these three flaws is CVE-2022-20708. According to Cisco, all
three vulnerabilities reside in the web-based management interface of these devices. A remote, unauthenticated
attacker could exploit these vulnerabilities by sending a specially crafted input to a vulnerable device. Successful
exploitation would grant an attacker arbitrary command execution privileges at the operating system level.

At least 8,400 RV34X devices are publicly accessible

According to searches conducted on Shodan, there are at least 8,400* publicly accessible RV34X devices.

*These results were captured on February 2, 2022

Proof of concept

In its advisory, Cisco says they are aware of proofs-of-concept (PoC) exploits for several of the vulnerabilities
patched. However, none of the PoCs were hosted on public repositories like GitHub at the time this blog was
published.

Solution

Cisco has released fixes for all 15 vulnerabilities for the RV340 and RV345 Series Routers, however a fix has not yet
been released for their RV160 and RV260 Series .

Identifying affected systems

A list of Tenable plugins to identify these vulnerabilities will appear here as they’re released.

Get more information

Join Tenable’s
Security Response Team on the Tenable Community.

Learn more about Tenable, the first Cyber Exposure platform
for holistic management of your modern attack surface.

Get a free 30-day
trial of Tenable.io Vulnerability Management.