CVE-2021-21261
Published Jan 14, 2021
Last updated 4 years ago
Overview
- Description
- Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. A bug was discovered in the `flatpak-portal` service that can allow sandboxed applications to execute arbitrary code on the host system (a sandbox escape). This sandbox-escape bug is present in versions from 0.11.4 and before fixed versions 1.8.5 and 1.10.0. The Flatpak portal D-Bus service (`flatpak-portal`, also known by its D-Bus service name `org.freedesktop.portal.Flatpak`) allows apps in a Flatpak sandbox to launch their own subprocesses in a new sandbox instance, either with the same security settings as the caller or with more restrictive security settings. For example, this is used in Flatpak-packaged web browsers such as Chromium to launch subprocesses that will process untrusted web content, and give those subprocesses a more restrictive sandbox than the browser itself. In vulnerable versions, the Flatpak portal service passes caller-specified environment variables to non-sandboxed processes on the host system, and in particular to the `flatpak run` command that is used to launch the new sandbox instance. A malicious or compromised Flatpak app could set environment variables that are trusted by the `flatpak run` command, and use them to execute arbitrary code that is not in a sandbox. As a workaround, this vulnerability can be mitigated by preventing the `flatpak-portal` service from starting, but that mitigation will prevent many Flatpak apps from working correctly. This is fixed in versions 1.8.5 and 1.10.0.
- Source
- security-advisories@github.com
- NVD status
- Analyzed
Social media
- Hype score
- Not currently trending
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 8.8
- Impact score
- 6
- Exploitability score
- 2
- Vector string
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Severity
- HIGH
CVSS 2.0
- Type
- Primary
- Base score
- 7.2
- Impact score
- 10
- Exploitability score
- 3.9
- Vector string
- AV:L/AC:L/Au:N/C:C/I:C/A:C
Weaknesses
- security-advisories@github.com
- CWE-74
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "041D999E-622C-4771-9819-57C6F1BE7056",
"versionEndExcluding": "1.8.5",
"versionStartIncluding": "0.11.4"
},
{
"criteria": "cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "FD8B7A39-7AB9-43AA-9B31-B2112B6D90CF",
"versionEndExcluding": "1.10.0",
"versionStartIncluding": "1.9.1"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73"
}
],
"operator": "OR"
}
]
}
]