Information disclosure in Samba

1) Link following

EUVDB-ID: #VU60187

Risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-44141

CWE-ID: CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Exploit availability: No

Description

The vulnerability allows a remote user to gain access to sensitive information.

The vulnerability exists due to insecure link following. A remote user with ability to write files to the exported part of the file system under a share via SMB1 unix extensions or via NFS can create a symlink to determine if a file or directory exists in an area of the server file system not exported under the share definition.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Samba: 1.9.16 - 4.15.4

External links

http://www.samba.org/samba/security/CVE-2021-44141.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

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.