#VU53147 Buffer overflow in Siemens products - CVE-2021-27386

Vulnerability identifier: #VU53147

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-27386

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
SIMATIC HMI Comfort Outdoor Panels 7” & 15”
Server applications / SCADA systems
SIMATIC HMI Comfort Panels 4”-22”
Server applications / SCADA systems
SIMATIC HMI KTP400F
Server applications / SCADA systems
SIMATIC HMI KTP700
Server applications / SCADA systems
SIMATIC HMI KTP700F
Server applications / SCADA systems
SIMATIC HMI KTP900
Server applications / SCADA systems
SIMATIC HMI KTP900F
Server applications / SCADA systems
SIMATIC WinCC Runtime Advanced
Server applications / SCADA systems

Vendor: Siemens

Description

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

The vulnerability exists due to a boundary error in the device layout handler on client side. A remote attacker can trigger memory corruption and cause a denial of service condition on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

SIMATIC HMI Comfort Outdoor Panels 7” & 15”: before 16

SIMATIC HMI Comfort Panels 4”-22”: before 16

SIMATIC HMI KTP400F: before 16

SIMATIC HMI KTP700: before 16

SIMATIC HMI KTP700F: before 16

SIMATIC HMI KTP900: before 16

SIMATIC HMI KTP900F: before 16

SIMATIC WinCC Runtime Advanced: before 16

---

External links
https://ics-cert.us-cert.gov/advisories/icsa-21-131-12
https://cert-portal.siemens.com/productcert/pdf/ssa-538778.pdf

---

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.