Hackers Weaponize Langflow Vulnerability to Launch Flodrix Botnet

A critical security flaw in Langflow, a widely adopted Python-based AI prototyping framework, is being actively exploited by cybercriminals to deploy the rapidly evolving Flodrix botnet.

Security researchers have confirmed that attackers are exploiting CVE-2025-3248, a remote code execution (RCE) vulnerability rated 9.8 on the CVSS scale, to compromise unpatched Langflow servers and enlist them in a powerful botnet capable of launching disruptive distributed denial-of-service (DDoS) attacks and exfiltrating sensitive data.

The Vulnerability: CVE-2025-3248

Langflow, with over 70,000 GitHub stars, is popular for building and deploying intelligent automation systems. Versions before 1.3.0 contain a critical flaw in the /api/v1/validate/code endpoint.

This endpoint, designed to validate user-submitted Python code, fails to enforce authentication and input validation. As a result, unauthenticated attackers can craft malicious POST requests embedding harmful code within function decorators or default arguments.

When processed, these payloads are executed in the server’s context, granting attackers remote code execution capabilities.

The vulnerability was added to the U.S. Cybersecurity and Infrastructure Security Agency’s (CISA) Known Exploited Vulnerabilities catalog on May 5, 2025, underscoring its active exploitation and severity.

Threat actors begin by scanning the internet for publicly exposed, vulnerable Langflow instances using tools like Shodan and FOFA. 

Using a publicly available proof-of-concept exploit, they achieve remote shell access, execute reconnaissance commands to gather system information, and then deploy a downloader script—typically named “docker”—to fetch and install the Flodrix malware.

Once installed, Flodrix establishes communication with its command-and-control (C and C) infrastructure over both TCP and the Tor network.

The malware is highly evasive: it self-deletes after execution unless specific parameters are met, removes forensic artifacts, and employs XOR-based string obfuscation to hide C and C addresses.

Flodrix also checks for hidden files to avoid reinfecting the same host and forks child processes with fake names to evade detection.

Flodrix is a sophisticated descendant of the LeetHozer malware family, but with enhanced stealth and attack features. It can:

• Launch multiple types of DDoS attacks (e.g., tcpraw, udpplain, handshake, tcplegit, ts3, udp)
• Perform extensive reconnaissance, dumping environment variables and scanning for network interfaces
• Enumerate and terminate suspicious processes, especially those running from /tmp or named watchdog, busybox, or systemd
• Send structured “KILLDETAIL” notifications to its C and C when it terminates processes, aiding attacker monitoring
• Use encrypted configurations and support new, obfuscated DDoS attack types.

Researchers warn that the campaign is ongoing, with attackers actively developing new downloader scripts and expanding Flodrix’s capabilities.

Organizations using Langflow versions before 1.3.0 are at critical risk, especially if their deployments are accessible from public networks.

Mitigation steps include:

• Immediately upgrading Langflow to version 1.3.0 or later, which introduces strict authentication on the vulnerable endpoint
• Restricting public access to Langflow endpoints
• Monitoring for indicators of compromise linked to the Flodrix botnet

Security vendors have updated detection rules to block exploitation attempts, but rapid patching remains essential as the botnet continues to evolve and target new victims.

Find this News Interesting! Follow us on Google News, LinkedIn, and X to Get Instant Updates