Echo like some other services, uses SPeL (Spring Expression Language) to process information - specifically around expected artifacts. Unlike orca, it was NOT restricting that context to a set of trusted classes, but allowing FULL JVM access. This enables a user to use arbitrary java classes which allow deep access to the system. This enables the ability to invoke commands, access files, etc.
Disable echo entirely.
2025.3.22025.4.22026.0.1Exploitability
AV:NAC:LPR:LUI:NScope
S:CImpact
C:HI:HA:H9.9/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H