---
cve: "CVE-2021-42753"
severity: "HIGH"
cvss: 8.1
epss: "1.1%"
vendor: "n/a"
kev: false
exploited: false
published: "2022-02-02 11:15:07"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-16T06:22:23+02:00"
---

# CVE-2021-42753

> 8.1 HIGH

## Beschreibung

An improper limitation of a pathname to a restricted directory ('Path Traversal') vulnerability [CWE-22] in FortiWeb management interface 6.4.1 and below, 6.3.15 and below, 6.2.x, 6.1.x, 6.0.x, 5.9.x and 5.8.x may allow an authenticated attacker to perform an arbitrary file and directory deletion in the device filesystem.

## CVSS-Vektor

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

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

## Schwachstellen-Klasse

- **CWE-22** — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

## Angriffsmuster (CAPEC)

- [CAPEC-64 — Using Slashes and URL Encoding Combined to Bypass Validation Logic](https://capec.mitre.org/data/definitions/64.html) _(Severity: High)_
- [CAPEC-76 — Manipulating Web Input to File System Calls](https://capec.mitre.org/data/definitions/76.html) _(Severity: Very High)_
- [CAPEC-78 — Using Escaped Slashes in Alternate Encoding](https://capec.mitre.org/data/definitions/78.html) _(Severity: High)_
- [CAPEC-79 — Using Slashes in Alternate Encoding](https://capec.mitre.org/data/definitions/79.html) _(Severity: High)_
- [CAPEC-126 — Path Traversal](https://capec.mitre.org/data/definitions/126.html) _(Severity: Very High)_

## Referenzen

- <https://fortiguard.com/psirt/FG-IR-21-158>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-42753) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_