---
cve: "CVE-2021-31349"
severity: "CRITICAL"
cvss: 9.8
epss: "1.7%"
vendor: "Juniper Networks"
kev: false
exploited: false
published: "2021-10-19 19:15:08"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-04T14:39:28+02:00"
---

# CVE-2021-31349

> 9.8 CRITICAL

## Beschreibung

The usage of an internal HTTP header created an authentication bypass vulnerability (CWE-287), allowing an attacker to view internal files, change settings, manipulate services and execute arbitrary code. This issue affects all Juniper Networks 128 Technology Session Smart Router versions prior to 4.5.11, and all versions of 5.0 up to and including 5.0.1.

## 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 |

## Schwachstellen-Klasse

- **CWE-287** — Improper Authentication
  When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

## Angriffsmuster (CAPEC)

- [CAPEC-22 — Exploiting Trust in Client](https://capec.mitre.org/data/definitions/22.html) _(Severity: High)_
- [CAPEC-57 — Utilizing REST's Trust in the System Resource to Obtain Sensitive Data](https://capec.mitre.org/data/definitions/57.html) _(Severity: Very High)_
- [CAPEC-114 — Authentication Abuse](https://capec.mitre.org/data/definitions/114.html) _(Severity: Medium)_
- [CAPEC-115 — Authentication Bypass](https://capec.mitre.org/data/definitions/115.html) _(Severity: Medium)_
- [CAPEC-151 — Identity Spoofing](https://capec.mitre.org/data/definitions/151.html) _(Severity: Medium)_
- [CAPEC-194 — Fake the Source of Data](https://capec.mitre.org/data/definitions/194.html) _(Severity: Medium)_
- [CAPEC-593 — Session Hijacking](https://capec.mitre.org/data/definitions/593.html) _(Severity: Very High)_
- [CAPEC-633 — Token Impersonation](https://capec.mitre.org/data/definitions/633.html) _(Severity: Medium)_

## ATT&CK-Techniken

- [T1040 — Network Sniffing](https://attack.mitre.org/techniques/T1040/)
- [T1548 — Abuse Elevation Control Mechanism](https://attack.mitre.org/techniques/T1548/)
- [T1185 — Browser Session Hijacking](https://attack.mitre.org/techniques/T1185/)
- [T1550.001 — Use Alternate Authentication Material:Application Access Tok](https://attack.mitre.org/techniques/T1550/001/)
- [T1563 — Remote Service Session Hijacking](https://attack.mitre.org/techniques/T1563/)
- [T1134 — Access Token Manipulation](https://attack.mitre.org/techniques/T1134/)

## Referenzen

- <https://kb.juniper.net/JSA11256>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-31349) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_