Risk | Medium |
Patch available | YES |
Number of vulnerabilities | 1 |
CVE-ID | CVE-2021-20254 |
CWE-ID | CWE-125 |
Exploitation vector | Local network |
Public exploit | N/A |
Vulnerable software Subscribe |
QNAP QTS Server applications / File servers (FTP/HTTP) QuTScloud Operating systems & Components / Operating system QuTS hero Hardware solutions / Firmware |
Vendor | QNAP Systems, Inc. |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
EUVDB-ID: #VU52748
Risk: Medium
CVSSv3.1: 4 [CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-20254
CWE-ID:
CWE-125 - Out-of-bounds read
Exploit availability: No
DescriptionThe vulnerability allows a remote user to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when mapping Windows group identities (SIDs) into unix group identities (gids), which resulted into negative idmap cache entries created in the Samba server process token. An attacker who can manage to trigger the vulnerability can crash the Samba server or potentially perform unauthorized actions on the system.
Install update from vendor's website.
Vulnerable software versionsQNAP QTS: before c4.5.5.1656 build 20210503
QuTScloud: before 4.5.3.1670 20210515
QuTS hero: before h4.5.3.1670 build 20210515
External linkshttp://www.qnap.com/en/security-advisory/qsa-21-27
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).
How the attacker can exploit this vulnerability?
The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.