Red Hat Enterprise Linux 8.1 update for flatpak

1) Improper Neutralization of Special Elements in Output Used by a Downstream Component

EUVDB-ID: #VU51443

Risk: Medium

CVSSv3.1: 4.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-21381

CWE-ID: CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to improper input validation within the "file forwarding" feature. By putting the special tokens `@@` and/or `@@u` in the Exec field of a Flatpak app's .desktop file, a malicious app publisher can trick flatpak into behaving as though the user had chosen to open a target file with their Flatpak app, which automatically makes that file available to the Flatpak app.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

flatpak (Red Hat package): 1.0.9-3.el8_1

Red Hat Enterprise Linux for ARM 64 - Extended Update Support: 8.1

Red Hat Enterprise Linux for Power, little endian - Extended Update Support: 8.1

Red Hat Enterprise Linux for IBM z Systems - Extended Update Support: 8.1

Red Hat Enterprise Linux for x86_64 - Extended Update Support: 8.1

Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 8.1

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 8.1

External links

http://access.redhat.com/errata/RHSA-2021:1074

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.