Red Hat update for samba4

1) Improper authentication

EUVDB-ID: #VU6628

Risk: Low

CVSSv4.0: 1.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2016-2125

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

The vulnerability allows a remote attacker on the local network to bypass Kerberos authentication.

The vulnerability exists due to design error when implementing Kerberos authentication. An attacker with access to local network can place a fake Samba server, intercept a valid general purpose Kerberos "Ticket Granting Ticket" (TGT) and fully impersonate the authenticated user or service.

Successful exploitation of the vulnerability may allow an attacker to bypass authentication process and gain access to otherwise restricted resources and services.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Scientific Computing: 6

Red Hat Enterprise Linux for IBM z Systems: 6

Red Hat Enterprise Linux Desktop: 6

Red Hat Enterprise Linux Workstation: 6

Red Hat Enterprise Linux Server: 6.0

CPE2.3

• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_scientific_computing:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_desktop:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_workstation:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server:6.0:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2017:0744

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.

2) Buffer overflow

EUVDB-ID: #VU6629

Risk: Medium

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

CVE-ID: CVE-2016-2126

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

The vulnerability allows a remote authenticated attacker to escalate privileges.

The vulnerability exists due to a boundary error within Kerberos PAC validation process in winbindd. A remote authenticated attacker can send a specially crafted request to vulnerable Samba server, trigger buffer overflow and execute arbitrary code on the server with elevated privileges.

Successful exploitation of the vulnerability may allow an attacker to execute arbitrary code with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Scientific Computing: 6

Red Hat Enterprise Linux for IBM z Systems: 6

Red Hat Enterprise Linux Desktop: 6

Red Hat Enterprise Linux Workstation: 6

Red Hat Enterprise Linux Server: 6.0

CPE2.3

• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_scientific_computing:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_desktop:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_workstation:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server:6.0:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2017:0744

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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