Red Hat Enterprise Linux 8.2 update for flatpak

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

EUVDB-ID: #VU51443

Risk: Medium

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

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): 1.6.2-4.el8_2

Red Hat Enterprise Linux Server - TUS: 8.2

CPE2.3

• cpe:2.3:a:red_hat:flatpak_redhat_package:1.6.2-4.el8_2:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server_-_tus:8.2:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2021:1073

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.