The vulnerability in MZ Automation lib60870 allows an attacker to craft an IEC 60870‑5‑104 I‑frame with an object count that exceeds the actual ASDU body size, causing the library function InformationObject_ParseObjectAddress to read one byte past the allocated message buffer. This out‑of‑bounds read can reveal arbitrary memory contents, potentially exposing sensitive control data or internal state. The weakness is a typical CWE‑125 buffer overread.

Any installation of MZ Automation lib60870 that has not yet been updated to version 2.4.1 or later is susceptible. The vendor’s advisory specifically targets earlier releases of the library that lack the bounds‑checking fix.

With a CVSS score of 6.9, the vulnerability is considered medium severity. The EPSS score of < 1% indicates a very low exploitation probability, and the vulnerability is not listed in the CISA KEV catalog, suggesting no widespread exploitation has been observed. The likely attack vector is remote, as the flaw is triggered by a crafted frame over the network protocol, so any device exposing IEC 60870‑5‑104 to untrusted networks could be targeted.