In issue 810 we pointed out to Symantec that they hadn't updated their unrar based unpacker for years, and it was vulnerable to dozens of publicly documented flaws.
I had expected Symantec to rebase on 5.4.2 (the latest version as of this writing), but they appear to have just backported fixes for the few issues I sent them.
Here are two known bugs in unrar that are fixed upstream, but not in Symantec's ancient code. If they continue to refuse to rebase, this might take a few iterations to shake the bugs out. Sigh.
As in issue 810, these are remote code execution vulnerabilities at the highest possible privilege level.
Proof of Concept: