I came to problem with this Can't open file in php if one of directories is a symlink
suhosin ducumentation said that suhosin.executor.allow_symlink
This flag reactivates symlink() when open_basedir is used, which is disabled by default in Suhosin >= 0.9.6. Allowing symlink() while open_basedir is used is actually a security risk.
Why it's security problem, what can happen if it's set to Off or when I use root directory in open_basedir?