PHP 4.0 Bug #5898: php crashes trying to estrdup nonexistant environment variables

From: Mario.Lorenz@geyer.kabeljournal.de Operating system: Linux, RedHat 6.1 PHP version: 4.0.1pl2 PHP Bug Type: Reproduceable crash Bug description: php crashes trying to estrdup nonexistant environment variables This is plain 4.0.1pl2 in CGI mode on a RedHat 6.1 (patched up) sytem, however with Apache 1.3.3 (admitted, its oldish). Setup is plain ./configure without any further options. Whenever trying run a php4 script on that machine, php crashes (and httpd displays the preliminary end of script error message). Researching the problem showed: It crashes in zend_alloc.c:289 (_estrdup) called by cgi_main Line 632 trying to estrdup the PATH_TRANSLATED environment variable. Since that environment variable is not set (this part I blame to my old apache) it tries to strlen(0) (as thats what was returned by getenv) and therefore segfaults. Verified that by putting a wrapper around the scrip that would set the PATH_TRANSLATED variable, and voila, all went OK. While I admit that in part this problem is caused by the old apache, I also hold that no program should ever segfault, in particularly no attack-exposed program like PHP.