---
cve: "CVE-2021-34523"
severity: "CRITICAL"
cvss: 9.0
epss: "100%"
vendor: "Microsoft"
kev: true
exploited: true
published: "2021-07-14 18:15:12"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-07T05:00:52+02:00"
---

# CVE-2021-34523

> 9.0 CRITICAL · ⚠️ CISA KEV (1769 Tage) · 🔓 Exploited

## Beschreibung

Microsoft Exchange Server Elevation of Privilege Vulnerability

## CVSS-Vektor

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

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

## Referenzen

- <https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34523>
- <http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html>
- <https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523>
- <https://www.zerodayinitiative.com/advisories/ZDI-21-822/>
- <https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-34523) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_