What is the CVSS score of CVE-2020-5653?

CVE-2020-5653 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 3.2%.

Melsec Iq Rj71Eip91 Firmware CVE-2020-5653

CRITICAL

Classic Buffer Overflow (CWE-120)

2020-11-02 vultures@jpcert.or.jp

Buffer Overflow Melsec Iq Rj71Eip91 Firmware Melsec Iq Rj71Pn92 Firmware Melsec Iq Rd81Dl96 Firmware Melsec Iq Rd81Mes96N Firmware Melsec Iq Rd81Opc96 Firmware

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Nov 02, 2020 - 21:15 nvd

CRITICAL 9.8

DescriptionNVD

Buffer overflow vulnerability in TCP/IP function included in the firmware of MELSEC iQ-R series (RJ71EIP91 EtherNet/IP Network Interface Module First 2 digits of serial number are '02' or before, RJ71PN92 PROFINET IO Controller Module First 2 digits of serial number are '01' or before, RD81DL96 High Speed Data Logger Module First 2 digits of serial number are '08' or before, RD81MES96N MES Interface Module First 2 digits of serial number are '04' or before, and RD81OPC96 OPC UA Server Module First 2 digits of serial number are '04' or before) allows a remote unauthenticated attacker to stop the network functions of the products or execute a malicious program via a specially crafted packet.

AnalysisAI

Buffer overflow vulnerability in TCP/IP function included in the firmware of MELSEC iQ-R series (RJ71EIP91 EtherNet/IP Network Interface Module First 2 digits of serial number are '02' or before,. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as Buffer Copy without Size Check (CWE-120), which allows attackers to overflow a buffer to corrupt adjacent memory. Buffer overflow vulnerability in TCP/IP function included in the firmware of MELSEC iQ-R series (RJ71EIP91 EtherNet/IP Network Interface Module First 2 digits of serial number are '02' or before, RJ71PN92 PROFINET IO Controller Module First 2 digits of serial number are '01' or before, RD81DL96 High Speed Data Logger Module First 2 digits of serial number are '08' or before, RD81MES96N MES Interface Module First 2 digits of serial number are '04' or before, and RD81OPC96 OPC UA Server Module First 2 digits of serial number are '04' or before) allows a remote unauthenticated attacker to stop the network functions of the products or execute a malicious program via a specially crafted packet. Affected products include: Mitsubishielectric Melsec Iq-Rj71Eip91 Firmware, Mitsubishielectric Melsec Iq-Rj71Pn92 Firmware, Mitsubishielectric Melsec Iq-Rd81Dl96 Firmware, Mitsubishielectric Melsec Iq-Rd81Mes96N Firmware, Mitsubishielectric Melsec Iq-Rd81Opc96 Firmware.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Always validate buffer sizes before copy operations. Use bounded functions (strncpy, snprintf). Enable compiler protections.