TLDR: OK to repeat someone else's old, unanswered question if (as a creditless newbie) I can't vote it up or comment or otherwise help bring it to attention?
Details: I encountered an issue and wanted to ask a technical question (on Super User, as it happens; but I guess the question is relevant to all Stack Exchange sites). It's a rather obscure issue, and I assumed I may be the first to ask about it (and was skeptical that anyone would have a resolution).
But as I started typing the title, there was a suggestion ("Questions that may already have your answer") that linked to a question that someone else already asked, which is the exact question I had. I was happy to find this (and of course stopped typing my redundant question), but unfortunately, no one answered it yet.
But now, I wanted to vote this question up - and I can't. As a newbie, I don't have enough reputation. I also wanted (in a comment) to ask the person who posted this whether he had already found an answer somehow (it's been a while since he posted his question). But I can't do that either, for the same reason.
In such case: is it legitimate to somehow repeat the question? Or is that "littering" the site?