---
cve: "CVE-2021-3939"
severity: "HIGH"
cvss: 7.8
epss: "35%"
vendor: "Ubuntu"
kev: false
exploited: false
published: "2021-11-17 04:15:06"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-14T07:08:12+02:00"
---

# CVE-2021-3939

> 7.8 HIGH · 🧪 PoC

## Beschreibung

Ubuntu-specific modifications to accountsservice (in patch file debian/patches/0010-set-language.patch) caused the fallback_locale variable, pointing to static storage, to be freed, in the user_change_language_authorized_cb function. This is reachable via the SetLanguage dbus function. This is fixed in versions 0.6.55-0ubuntu12~20.04.5, 0.6.55-0ubuntu13.3, 0.6.55-0ubuntu14.1.

## CVSS-Vektor

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

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

## Referenzen

- <https://ubuntu.com/security/notices/USN-5149-1>
- <https://bugs.launchpad.net/ubuntu/+source/accountsservice/+bug/1950149>
- <http://packetstormsecurity.com/files/172848/Ubuntu-accountsservice-Double-Free-Memory-Corruption.html>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-3939) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_