Debian update for samba

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU20809

Risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-10197

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to an error related to caching of responses when the 'wide links' option is explicitly set to 'yes' and either 'unix extensions = no' or 'allow insecure wide links = yes' is set in addition. A remote attacker can that does not have access to a share can send a series of request to an SMB share and gain access to the global root directory on the system.

Successful exploitation of the vulnerability may allow an attacker to read or modify arbitrary files on the system. Note, that unix permissions enforced by kernel will still apply.

Mitigation

Update the affected package to version: 2:4.9.5+dfsg-5+deb10u1.

Vulnerable software versions

samba (Debian package): 2:4.9.4+dfsg-1 - 2:4.9.5+dfsg-5

External links

http://www.debian.org/security/2019/dsa-4513

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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