CVE-2021-41133

Flatpak is a system for building, distributing, and running sandboxed desktop applications on Linux. In versions prior to 1.10.4 and 1.12.0, Flatpak apps with direct access to AF_UNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can trick portals and other host-OS services into treating the Flatpak app as though it was an ordinary, non-sandboxed host-OS process. They can do this by manipulating the VFS using recent mount-related syscalls that are not blocked by Flatpak's denylist seccomp filter, in order to substitute a crafted `/.flatpak-info` or make that file disappear entirely. Flatpak apps that act as clients for AF_UNIX sockets such as those used by Wayland, Pipewire or pipewire-pulse can escalate the privileges that the corresponding services will believe the Flatpak app has. Note that protocols that operate entirely over the D-Bus session bus (user bus), system bus or accessibility bus are not affected by this. This is due to the use of a proxy process `xdg-dbus-proxy`, whose VFS cannot be manipulated by the Flatpak app, when interacting with these buses. Patches exist for versions 1.10.4 and 1.12.0, and as of time of publication, a patch for version 1.8.2 is being planned. There are no workarounds aside from upgrading to a patched version.

CVSS v3.0 7.8 HIGH
CVSS v2.0 4.6 MEDIUM

7.8^/10

CVSS v3.0 : HIGH

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

4.6^/10

CVSS v2.0 : MEDIUM

V2 Legend

Vector : AV:L/AC:L/Au:N/C:P/I:P/A:P

Exploitability : 3.9 / Impact : 6.4

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://github.com/flatpak/flatpak/commit/1330662f33a55e88bfe18e76de28b7922d91a999	Patch Third Party Advisory
https://github.com/flatpak/flatpak/commit/a10f52a7565c549612c92b8e736a6698a53db330	Patch Third Party Advisory
https://github.com/flatpak/flatpak/commit/4c34815784e9ffda5733225c7d95824f96375e36	Patch Third Party Advisory
https://github.com/flatpak/flatpak/commit/89ae9fe74c6d445bb1b3a40e568d77cf5de47e48	Patch Third Party Advisory
https://github.com/flatpak/flatpak/commit/462fca2c666e0cd2b60d6d2593a7216a83047aaf	Patch Third Party Advisory
https://github.com/flatpak/flatpak/commit/e26ac7586c392b5eb35ff4609fe232c52523b2cf	Patch Third Party Advisory
https://github.com/flatpak/flatpak/security/advisories/GHSA-67h7-w3jq-vh4q	Patch Third Party Advisory
https://github.com/flatpak/flatpak/commit/26b12484eb8a6219b9e7aa287b298a894b2f34ca	Patch Third Party Advisory
https://github.com/flatpak/flatpak/commit/9766ee05b1425db397d2cf23afd24c7f6146a69f	Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/R5656ONDP2MGKIJMKEC7N2NXCV27WGTC/	Mailing List Third Party Advisory
https://www.debian.org/security/2021/dsa-4984	Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/10/26/9	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/T5DKCYRC6MFSTFCUP4DELCOUUP3SFEFX/	Mailing List Third Party Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:flatpak:flatpak::::::::
	cpe:2.3:a:flatpak:flatpak::::::::
	cpe:2.3:a:flatpak:flatpak::::::::

Configuration 2 (hide)

cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

Configuration 3 (hide)

OR	cpe:2.3:o:fedoraproject:fedora:33:::::::*
	cpe:2.3:o:fedoraproject:fedora:34:::::::*

Information

Published : 2021-10-08 07:15

Updated : 2021-12-03 19:04

NVD link : CVE-2021-41133

Mitre link : CVE-2021-41133

JSON object : View

CWE

CWE-20

Improper Input Validation

Products Affected

debian

debian_linux

flatpak

flatpak

fedoraproject

fedora

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Patches exist for versions 1.10.4 and 1.12.0, and as of time of publication, a patch for version 1.8.2 is being planned. There are no workarounds aside from upgrading to a patched version."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "en", "value": "CWE-20"}]}]}, "data_version": "4.0", "CVE_data_meta": {"ID": "CVE-2021-41133", "ASSIGNER": "security-advisories@github.com"}}, "impact": {"baseMetricV2": {"cvssV2": {"version": "2.0", "baseScore": 4.6, "accessVector": "LOCAL", "vectorString": "AV:L/AC:L/Au:N/C:P/I:P/A:P", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "LOW", "availabilityImpact": "PARTIAL", "confidentialityImpact": "PARTIAL"}, "severity": "MEDIUM", "acInsufInfo": false, "impactScore": 6.4, "obtainAllPrivilege": false, "exploitabilityScore": 3.9, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}, "baseMetricV3": {"cvssV3": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}}, "publishedDate": "2021-10-08T14:15Z", "configurations": {"nodes": [{"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "1.8.2"}, {"cpe23Uri": "cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "1.10.4", "versionStartIncluding": "1.10.0"}, {"cpe23Uri": "cpe:2.3:a:flatpak:flatpak:*:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "1.12.1", "versionStartIncluding": "1.11.1"}]}, {"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true}]}, {"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true}, {"cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true}]}], "CVE_data_version": "4.0"}, "lastModifiedDate": "2021-12-04T03:04Z"}

7.8 /10