Entry for CVE-2010-2094 says:
Multiple format string vulnerabilities in the phar
extension in PHP 5.3 before 5.3.2 allow context-dependent
attackers to obtain sensitive information (memory
contents) and possibly execute arbitrary code via a
crafted phar:// URI that is not properly handled by the
(1) phar_stream_flush, (2) phar_wrapper_unlink,
(3) phar_parse_url, or (4) phar_wrapper_open_url functions
in ext/phar/stream.c; and the (5) phar_wrapper_open_dir
function in ext/phar/dirstream.c, which triggers errors
in the php_stream_wrapper_log_error function.
PECL source code for PHAR extension shares the same code,
so it is vulnerable too.