Privilege escalation in QNAP operating systems

1) Input validation error

EUVDB-ID: #VU71332

Risk: Low

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2023-22809

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists within the sudoedit (aka -e) feature due to insufficient validation of user-supplied input passed in the user-provided environment variables (SUDO_EDITOR, VISUAL, and EDITOR). The problem exists because a user-specified editor may contain a "--" argument that defeats a protection mechanism, e.g., an EDITOR='vim -- /path/to/extra/file' value. A local user can append arbitrary entries to the list of files to process and escalate privileges on the system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

QuTScloud: All versions

QVP (QVR Pro appliances): All versions

QuTS hero: before h5.0.1.2348 build 20230324

QNAP QTS: before 5.0.1.2346 20230322

CPE2.3

• cpe:2.3:o:qnap_systems:qutscloud:*:*:*:*:*:*:*:*
• cpe:2.3:h:qnap_systems:qvp_qvr_pro_appliances:*:*:*:*:*:*:*:*
• cpe:2.3:h:qnap_systems:quts-hero:*:*:*:*:*:*:*:*
• cpe:2.3:a:qnap_systems:qnap_qts:*:*:*:*:*:*:*:*

External links

https://www.qnap.com/en/security-advisory/qsa-23-11

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.