SB2021041407 - Multiple vulnerabilities in Siemens SIMOTICS CONNECT 400

Description

This security bulletin contains information about 3 vulnerabilities.

1) Improper Null Termination (CVE-ID: CVE-2020-27736)

CWE-ID: CWE-170 - Improper Null Termination

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

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

The vulnerability exists due to the DNS domain name label parsing functionality does not properly validate the null-terminated name in DNS-responses. A remote attacker can cause a denial of service condition or leak the read memory.

2) Out-of-bounds read (CVE-ID: CVE-2020-27737)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

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

The vulnerability exists due to a boundary condition in the DNS response parsing functionality. A remote attacker can trigger out-of-bounds read error and read contents of memory on the system or cause a denial of service (DoS) condition.

3) Access of Memory Location After End of Buffer (CVE-ID: CVE-2020-27738)

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

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

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

The vulnerability exists due to the DNS domain name record decompression functionality does not properly validate the pointer offset values. A remote attacker can cause a denial of service condition on the target system.

Remediation

Install update from vendor's website.

References

• https://ics-cert.us-cert.gov/advisories/icsa-21-103-13
• https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf