---
cve: "CVE-2018-6789"
severity: "CRITICAL"
cvss: 9.8
epss: "82.1%"
vendor: "n/a"
kev: true
exploited: true
published: "2018-02-08 23:29:01"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T17:26:01+02:00"
---

# CVE-2018-6789

> 9.8 CRITICAL · ⚠️ CISA KEV (1782 Tage) · 🔓 Exploited · 🧪 PoC

## Beschreibung

An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1. By sending a handcrafted message, a buffer overflow may happen. This can be used to execute code remotely.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Exploit-Evidenz

- [EDB-45671 — exim 4.90 - Remote Code Execution](https://www.exploit-db.com/exploits/45671)
- [EDB-44571 — Exim < 4.90.1 - 'base64d' Remote Code Execution](https://www.exploit-db.com/exploits/44571)

## Patch verfügbar (OSV)

- 062990cc1b2f9e5d82a413b53c8f0569075de700 (Commit)

## Referenzen

- <https://exim.org/static/doc/security/CVE-2018-6789.txt>
- <http://www.openwall.com/lists/oss-security/2018/02/07/2>
- <https://usn.ubuntu.com/3565-1/>
- <http://openwall.com/lists/oss-security/2018/02/10/2>
- <http://www.securitytracker.com/id/1040461>
- <https://www.debian.org/security/2018/dsa-4110>
- <https://www.exploit-db.com/exploits/44571/>
- <https://lists.debian.org/debian-lts-announce/2018/02/msg00009.html>
- <https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1>
- <https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/>
- <http://www.securityfocus.com/bid/103049>
- <https://www.exploit-db.com/exploits/45671/>
- <http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.html>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2018-6789) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_