Hitachi Energy GMS600 RSA decryption timing attack
Free public brief. The indicators, the detections with Splunk SPL already written (plus Elastic and KQL where they apply), and a Slack alert the next time this touches a vendor you run are in the app — free account, no card.
OpenSSL timing-based side-channel vulnerability in GMS600 1.3.0–1.3.1 allows plaintext recovery via Bleichenbacher-style attack.
Hitachi Energy GMS600 versions 1.3.0 and 1.3.1 contain CVE-2022-4304, a timing-based side-channel vulnerability in the bundled OpenSSL component affecting RSA decryption across all padding modes (PKCS#1 v1.5, RSA-OAEP, RSA-SVE). An attacker who observes a genuine TLS connection can send a large number of trial decryption messages to the target server, measuring response times to infer the pre-master secret and subsequently decrypt the application data from the original connection. This is a variant of the Bleichenbacher attack exploiting observable timing discrepancies in RSA processing.
The vulnerability is rated CWE-203 (Observable Discrepancy). GMS600 is a control system product deployed worldwide in critical manufacturing. Affected versions are 1.3.0 and 1.3.1; remediation is to upgrade to version 1.3.2. The advisory does not indicate active exploitation in the wild. Defenders should prioritize patching exposed instances and apply general mitigation: network segmentation, ingress IP allowlisting, rate limiting, and isolation of process control networks from the internet.
Mentioned in this report
Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-26-141-01
What this brief leaves out
This page is the free tier: the write-up, the severity, the names. In the app the same report carries its extracted indicators, its detections (Splunk SPL already written, plus Elastic and Microsoft KQL where they apply), the actors and CVEs it names as live profiles, and the vendor research on the same campaign — the primary source the news paraphrased, cited and read directly.
It sits in a corpus of 13,854 reports from 146 sources, 616 of them written in the last seven days, and it grows through the day.
A new account starts with three days of all of it, no card, then keeps the government and CERT reporting free. Name the vendors you run and Slack hears about the reports that touch them — about forty a week that are yours, not the four hundred that are not.
Create a free account What it costs