#VU23507 Use of out-of-range pointer offset in Samba - CVE-2019-14861

Vulnerability identifier: #VU23507

Vulnerability risk: Low

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

CVE-ID: CVE-2019-14861

CWE-ID: CWE-823

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Samba
Server applications / Directory software, identity management

Vendor: Samba

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 - 4.0.26, 4.1.0 - 4.11.2, 4.2.0 - 4.2.14, 4.3.0 - 4.3.13, 4.4.0 rc4 - 4.4.16, 4.5.0 - 4.5.16, 4.6.0 - 4.6.16, 4.7.0 - 4.7.12, 4.8.0 - 4.8.12, 4.9.0 - 4.9.16

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External links
https://www.samba.org/samba/security/CVE-2019-14861.html

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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.