Access of Memory Location After End of Buffer in DNS Module of Siemens Nucleus Products

1) Access of Memory Location After End of Buffer

EUVDB-ID: #VU52203

Risk: Medium

CVSSv3.1: 3.4 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-25677

CWE-ID: CWE-788 - Access of Memory Location After End of Buffer

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the DNS client does not properly randomize DNS transaction IDs. A remote attacker can poison the DNS cache or spoof DNS resolving. 

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Nucleus ReadyStart: 2017.02.3

Nucleus NET: All versions

VSTAR: All versions

Nucleus Source Code: All versions

Nucleus RTOS: All versions

Nucleus 4: before 4.1.0

External links

http://cert-portal.siemens.com/productcert/txt/ssa-705111.txt

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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