Directory traversal vulnerability in the installer in PEAR 1.0 through 1.5.3 allows user-assisted remote attackers to overwrite arbitrary files via a .. (dot dot) sequence in the (1) install-as attribute in the file element in package.xml 1.0 or the (2) as attribute in the install element in package.xml 2.0. NOTE: it could be argued that this does not cross privilege boundaries in typical installations, since the code being installed could perform the same actions.
https://exchange.xforce.ibmcloud.com/vulnerabilities/34482
http://www.vupen.com/english/advisories/2007/1926
http://www.ubuntu.com/usn/usn-462-1
http://www.securityfocus.com/bid/24111
http://www.mandriva.com/security/advisories?name=MDKSA-2007:110
http://secunia.com/advisories/25372