# CVE-2017-17562: Embedthis GoAhead Remote Code Execution Vulnerability

- Exploited (CISA KEV): yes, added 2021-12-10
- Published: 2017-12-12
- CVSS: 8.1 HIGH (v3.1)
- EPSS: 97.1% (100th percentile)
- CWE: CWE-20

Embedthis GoAhead before 3.6.5 allows remote code execution if CGI is enabled and a CGI program is dynamically linked. This is a result of initializing the environment of forked CGI scripts using untrusted HTTP request parameters in the cgiHandler function in cgi.c. When combined with the glibc dynamic linker, this behaviour can be abused for remote code execution using special parameter names such as LD_PRELOAD. An attacker can POST their shared object payload in the body of the request, and reference it using /proc/self/fd/0.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | Before feed history | — | — |
| AWS | Before feed history | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | Before feed history | — | — |
| Fastly | Before feed history | — | — |
| F5 | Before feed history | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | Before feed history | — | — |

## Our test (measured)

- OWASP Core Rule Set 4.25.0, paranoia level 1, anomaly threshold 5, default CRS settings: passed (0 of 1 requests blocked), template CVE-2017-17562, 2026-11-02
- OWASP Core Rule Set 4.25.0, paranoia level 2, anomaly threshold 5, default CRS settings: passed (0 of 1 requests blocked), template CVE-2017-17562, 2026-11-02

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2017-17562 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2017-17562