CVE-2024-2389

What it actually does

CVE-2024-2389 is an unauthenticated operating-system command injection vulnerability in the Flowmon management interface. A remote attacker with network access to the management interface can send crafted HTTP requests that cause the appliance to execute arbitrary system commands. Because the flaw requires no authentication, no user interaction, and has network attack vector with scope change, successful exploitation can lead to full compromise of the Flowmon system, including command execution, data access, configuration tampering, persistence, and disruption of monitoring functions. Affected versions are Flowmon prior to 11.1.14 and prior to 12.3.5.

Why it matters to the business

A compromised Flowmon appliance can become a foothold inside the network, exposing traffic-monitoring data, credentials or integration secrets stored on the system, and enabling attackers to pivot further into monitored environments. Operationally, attackers could disable or manipulate network visibility, interfere with incident detection, or use the appliance to stage malware and lateral movement. The risk is high because the vulnerability has a CVSS score of 10.0, a very high EPSS score of 0.92944, and weaponized exploitation is available; although it is not currently listed in CISA KEV, organizations should treat exposed management interfaces as urgent remediation targets.

How an attack unfolds

An attacker first identifies an internet-exposed or internally reachable Flowmon management interface. They then send a crafted unauthenticated HTTP request to the vulnerable management functionality containing shell metacharacters or encoded command payloads. The vulnerable server-side component passes attacker-controlled input to the operating system without proper sanitization, causing the appliance to execute the supplied command. The attacker typically validates execution with a benign command, then retrieves additional tooling using curl or wget, opens a reverse shell, creates persistence, enumerates configuration and credentials, and uses the compromised appliance as a trusted network-monitoring foothold. Because Flowmon appliances often have broad visibility into network traffic, compromise may also assist reconnaissance and evasion.

How to fix it

Upgrade Flowmon to a fixed release immediately: version 11.1.14 or later for the 11.x branch, or version 12.3.5 or later for the 12.x branch. If immediate upgrade is not possible, restrict access to the Flowmon management interface using VPN, allowlisted administrative IP ranges, firewall rules, and network segmentation. Do not expose the management interface directly to the internet. Disable or remove unnecessary integrations and rotate credentials, API tokens, SSH keys, and certificates stored on or used by the appliance if compromise is suspected. After patching, review the appliance for persistence mechanisms, unexpected files, unauthorized users, modified startup jobs, and outbound connections before returning it to normal trust.

How to confirm the fix worked

Confirm the installed Flowmon version is 11.1.14 or later, or 12.3.5 or later, depending on the deployed branch. Verify that the management interface is not internet-accessible unless explicitly required and protected by strong access controls. Run an authenticated configuration review or vendor-supported vulnerability scan to confirm the fixed build is installed. From network controls, confirm only approved administrative sources can reach the management interface. Review recent web access logs and system logs for pre-patch exploitation attempts, especially requests containing shell metacharacters, URL-encoded command separators, or references to common payload download tools. If available, test with a non-destructive vendor-approved detection check rather than public exploit code.

Typical attack path

1. Discover a Flowmon management interface exposed to the internet or reachable from a compromised internal host.
2. Fingerprint the Flowmon version or infer vulnerability based on management interface behavior.
3. Send a crafted unauthenticated HTTP request containing command-injection syntax to the vulnerable management endpoint.
4. Confirm command execution through HTTP response behavior, timing, DNS callback, or outbound network connection.
5. Execute reconnaissance commands such as whoami, id, uname, ip addr, ps, and environment/configuration listing.
6. Download or stage payloads using curl, wget, Python, Perl, or shell redirection.
7. Establish interactive access, commonly through a reverse shell or deployed web-accessible script.
8. Harvest local configuration, credentials, API tokens, certificates, or integration secrets.
9. Attempt persistence, privilege escalation, log cleanup, and lateral movement into adjacent systems.

How to detect it

To determine whether exploitation already occurred, collect and review Flowmon management web access logs, reverse proxy logs, firewall logs, appliance system logs, authentication logs, shell history, process execution telemetry if available, and outbound network telemetry. Look for unauthenticated HTTP requests to the management interface containing command separators such as semicolons, pipes, backticks, $(), URL-encoded equivalents, or payloads invoking shell utilities. Investigate any Flowmon appliance initiating unusual outbound connections, especially to unknown public IPs over HTTP, HTTPS, DNS, SSH, or high ports shortly after suspicious inbound requests. On the appliance, look for unexpected child processes spawned by web/application services, newly created files in web directories or temporary directories, unauthorized users, new SSH authorized_keys entries, cron entries, modified startup scripts, and evidence of tools such as curl, wget, nc, bash, sh, python, perl, or chmod being invoked. Because weaponized exploitation is available and the EPSS probability is high, absence from KEV should not be treated as absence of exploitation.

• /service.pdfs/confluence
• ;id
• %3Bid
• ;whoami
• %3Bwhoami
• ;uname
• %3Buname
• ;cat%20/etc/passwd
• %3Bcat%20%2Fetc%2Fpasswd
• |id
• %7Cid
• `id`
• %60id%60
• $(id)
• %24%28id%29
• /bin/sh
• /bin/bash
• bash -c
• sh -c
• curl http
• curl https
• wget http
• wget https
• chmod +x
• nc -e
• /dev/tcp/
• python -c
• perl -e
• /etc/passwd
• /etc/shadow
• /root/.ssh/authorized_keys
• /tmp/
• /var/tmp/
• crontab -e
• /etc/cron.d/
• /etc/rc.local

What your security team should do

• Patch all Flowmon appliances to 11.1.14, 12.3.5, or later as the highest priority, especially any management interface reachable from untrusted networks.
• Immediately restrict management-interface access to approved administrative networks or VPN-only access.
• Inventory Flowmon deployments and confirm no unsupported or unknown instances remain exposed.
• Hunt historical logs for unauthenticated command-injection attempts and outbound callbacks from Flowmon appliances.
• If exploitation is suspected, isolate the appliance, preserve logs and disk artifacts, rotate credentials and tokens, and rebuild from trusted media if integrity cannot be assured.
• Monitor for outbound connections from Flowmon appliances to unfamiliar IPs, dynamic DNS domains, paste sites, file-sharing services, and command-and-control infrastructure.
• Review local users, SSH keys, cron jobs, startup scripts, web-accessible directories, and recently modified files for persistence.
• Add SIEM detections for command-injection patterns against Flowmon management URLs and for suspicious child processes spawned by web server or application service accounts.