I have only seen these photos, but I can't tell from the pictures that there's any significant corrosion present on the portion of the cable strands that is visible. What remains of the conduit they were in is visible, but I can't tell if the individual strands are also coated or if that's bare metal. The cables emerged through the bottom of a kitchen cabinet, but not the sink cabinet.
Coincidentally, the homeowner had a plumbing leak in the upstairs bathroom that ran down the walls and flooded the kitchen. The leak started several days after the cables were first observed, and so far there is no reason to think the two events are related. The cabinet was actually removed as part of the kitchen flood remediation. I don't know if the spots on the wall are mold, and if they are related to the plumbing failure, or what. (I am friendly with the property manager, not the homeowner, and am not privy to all the details of the situation.)
The immediate "solution" was to cut off the loop that emerged. From what I understand the homeowner is investigating permanent options. This is a townhouse complex with multiple units sharing a monolithic slab, but I don't know if this cable ran front-to-back only through one home, or crosswise across the entire length of the slab under multiple homes. From what I understand, the HOA is actually not responsible for foundation issues, which seems weird, but apparently that's how the community's governing documents are written.
