Plaintext storage of a password vulnerability in IDEC PLCs (FC6A Series MICROSmart All-in-One CPU module v2.32 and earlier, FC6A Series MICROSmart Plus CPU module v1.91 and earlier, WindLDR v8.19.1 and earlier, WindEDIT Lite v1.3.1 and earlier, and Data File Manager v2.12.1 and earlier) allows an attacker to obtain the PLC Web server user credentials from file servers, backup repositories, or ZLD files saved in SD cards. As a result, the attacker may access the PLC Web server and hijack the PLC, and manipulation of the PLC output and/or suspension of the PLC may be conducted.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-20827
• https://jvn.jp/en/vu/JVNVU92279973/index.html
• https://www.idec.com/home/lp/pdf/2021-12-24-PLC.pdf