Legacy CGI Email Script (CVE‑2000‑0411) Leaks Env Variables & Can Lead to Arbitrary Code Execution
What It Is — CVE‑2000‑0411 is a classic web‑application flaw in a CGI‑bin script that processes e‑mail requests. The script appends any URL parameters directly to the sendmail command and echoes back environment variables. An attacker can therefore (1) enumerate server environment data by adding extra query parameters, (2) manipulate the “To” address to send spam, and (3) craft a payload that is passed to the sendmail binary, achieving arbitrary code execution on the host. The vulnerability was publicly disclosed in 2000 and remains exploitable on any legacy system that still runs the unpatched script. No vendor‑issued patch exists; mitigation requires removal or replacement of the script and strict input sanitisation.
Affected Products — Any web server running the vulnerable CGI‑bin e‑mail script (commonly found on legacy Apache, Nginx, or custom CGI deployments).
Why It Matters for Trust & Control Assurance — The issue tests the control objective of secure development and input validation. Demonstrating that you have documented secure‑coding policies, regular code reviews, and evidence of remediation directly supports multiple frameworks (e.g., NIST CSF 2.0, ISO 27001).
Recommended Actions
- Inventory all web‑applications for legacy CGI scripts that send e‑mail.
- Remove or replace the vulnerable script with a modern, parameter‑safe mailing library.
- Apply input‑validation controls and log any attempts to invoke the script.
- Capture remediation evidence in your control‑mapping repository for audit readiness.
Source: SANS Internet Storm Center – The Classics Return: Vulnerable E‑Mail Scripts