Multiple vulnerabilities in Samba

Published: 2019-12-10

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2019-14870 CVE-2019-14861
CWE-ID	CWE-358 CWE-823
Exploitation vector	Local network
Public exploit	N/A
Vulnerable software	Samba Server applications / Directory software, identity management
Vendor	Samba

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Improperly implemented security feature

EUVDB-ID: #VU23470

Risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-14870

CWE-ID: CWE-358 - Improperly Implemented Security Check for Standard

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass certain security restrictions.

The vulnerability exists due to incorrect implementation of the DelegationNotAllowed Kerberos feature restriction ("delegation_not_allowed" user attribute) that is not applied when processing protocol transmission requests (S4U2Self) in the AD DC KDC. A remote authenticated user can gain access to sensitive information and functionality within the AD domain.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Samba: 4.0.0 - 4.11.2

CPE2.3

External links

http://www.samba.org/samba/security/CVE-2019-14870.html

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.

2) Use of out-of-range pointer offset

EUVDB-ID: #VU23507

Risk: Low

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

CVE-ID: CVE-2019-14861

CWE-ID: CWE-823 - Use of Out-of-range Pointer Offset

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to an error when processing DNS records in ldb_qsort() and dns_name_compare() function within the dnsserver RPC pipe. A remote authenticated user can register a zone with an existing name but in different register and force Samba to read memory prior to the list of DNS entries when responding to DnssrvEnumRecords() or DnssrvEnumRecords2() calls. This will trigger Samba to follow invalid memory as a pointer and lead to DoS of the DNS management server.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Samba: 4.0.0 - 4.11.2

CPE2.3

External links

http://www.samba.org/samba/security/CVE-2019-14861.html

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.