CVE - CVE-2021-43860

CVE-ID
CVE-2021-43860	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
Flatpak is a Linux application sandboxing and distribution framework. Prior to versions 1.12.3 and 1.10.6, Flatpak doesn't properly validate that the permissions displayed to the user for an app at install time match the actual permissions granted to the app at runtime, in the case that there's a null byte in the metadata file of an app. Therefore apps can grant themselves permissions without the consent of the user. Flatpak shows permissions to the user during install by reading them from the "xa.metadata" key in the commit metadata. This cannot contain a null terminator, because it is an untrusted GVariant. Flatpak compares these permissions to the actual metadata, from the "metadata" file to ensure it wasn't lied to. However, the actual metadata contents are loaded in several places where they are read as simple C-style strings. That means that, if the metadata file includes a null terminator, only the content of the file from before the terminator gets compared to xa.metadata. Thus, any permissions that appear in the metadata file after a null terminator are applied at runtime but not shown to the user. So maliciously crafted apps can give themselves hidden permissions. Users who have Flatpaks installed from untrusted sources are at risk in case the Flatpak has a maliciously crafted metadata file, either initially or in an update. This issue is patched in versions 1.12.3 and 1.10.6. As a workaround, users can manually check the permissions of installed apps by checking the metadata file or the xa.metadata key on the commit metadata.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
CONFIRM:https://github.com/flatpak/flatpak/security/advisories/GHSA-qpjc-vq3c-572j URL:https://github.com/flatpak/flatpak/security/advisories/GHSA-qpjc-vq3c-572j DEBIAN:DSA-5049 URL:https://www.debian.org/security/2022/dsa-5049 FEDORA:FEDORA-2022-825ca6bf2b URL:https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/APFTBYGJJVJPFVHRXUW5PII5XOAFI4KH/ GENTOO:GLSA-202312-12 URL:https://security.gentoo.org/glsa/202312-12 MISC:https://github.com/flatpak/flatpak/commit/54ec1a482dfc668127eaae57f135e6a8e0bc52da URL:https://github.com/flatpak/flatpak/commit/54ec1a482dfc668127eaae57f135e6a8e0bc52da MISC:https://github.com/flatpak/flatpak/commit/65cbfac982cb1c83993a9e19aa424daee8e9f042 URL:https://github.com/flatpak/flatpak/commit/65cbfac982cb1c83993a9e19aa424daee8e9f042 MISC:https://github.com/flatpak/flatpak/commit/93357d357119093804df05acc32ff335839c6451 URL:https://github.com/flatpak/flatpak/commit/93357d357119093804df05acc32ff335839c6451 MISC:https://github.com/flatpak/flatpak/commit/ba818f504c926baaf6e362be8159cfacf994310e URL:https://github.com/flatpak/flatpak/commit/ba818f504c926baaf6e362be8159cfacf994310e MISC:https://github.com/flatpak/flatpak/commit/d9a8f9d8ccc0b7c1135d0ecde006a75d25f66aee URL:https://github.com/flatpak/flatpak/commit/d9a8f9d8ccc0b7c1135d0ecde006a75d25f66aee MISC:https://github.com/flatpak/flatpak/releases/tag/1.10.6 URL:https://github.com/flatpak/flatpak/releases/tag/1.10.6 MISC:https://github.com/flatpak/flatpak/releases/tag/1.12.3 URL:https://github.com/flatpak/flatpak/releases/tag/1.12.3
Assigning CNA
GitHub (maintainer security advisories)
Date Record Created
20211116	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20211116)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
This is an record on the CVE List, which provides common identifiers for publicly known cybersecurity vulnerabilities.
Search CVE Using Keywords: You can also search by reference using the CVE Reference Maps.
For More Information: CVE Request Web Form (select "Other" from dropdown)