# CVE-2019-16928: Exim Out-of-bounds Write Vulnerability

- Exploited (CISA KEV): yes, added 2022-03-03
- Published: 2019-09-27
- CVSS: 9.8 CRITICAL (v3.1)
- EPSS: 41.6% (99th percentile)
- CWE: CWE-787

Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846. There is a heap-based buffer overflow in string_vformat in string.c involving a long EHLO command.

## 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 | — | — |

"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-2019-16928 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2019-16928