-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 QITEST1 SECURITY ADVISORY #005 wwwoffle-2.7b and prior segfaults with negative Content-Length value PROGRAM DESCRIPTION WWWOFFLE, World Wide Web Offline Explorer, is a proxy HTTP/FTP server for computers with dial-up internet access. DETAILS When processing http requests, wwwoffled misinterprets the "Content-Length" header field: it fails to handle negative values properly. Consequently, if receiving a negative integer, program segfaults in memcpy(), because its size argument (size_t n) should be an unsigned integer. Remote overflow exploitation may be possible. Only child process dies on segfault, so this does not constitutes a denial of service vulnerability effectively. SOLUTION wwwoffle_2.7c fixes this flaw. Alternatively, you can use the following patch: ==8< wwwoffle-2.7b.patch - --- wwwoffle-2.7b-old/src/parse.c Sat Mar 23 15:28:36 2002 +++ wwwoffle-2.7b/src/parse.c Fri Jul 12 16:52:46 2002 @@ -180,7 +180,7 @@ if(!strcmp("POST",(*request_head)->method) || !strcmp("PUT",(*request_head)->method)) { - - if(length==-1) + if(length < 0) {free(url);return(NULL);} *request_body=CreateBody(length); ==8< -- ------------------------------------------- ---- q1-- ---------------------------------------- -- ------------------------------------------- Web: http://bespin.org/~qitest1 GPG public key: http://bespin.org/~qitest1/qitest1.gpg.key - -------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE9Nmt+IrsshIyVmPkRAiWmAJ4rpSSEazUu5eR/JDNZx5aN+2o1iACggnOZ tyltTOlBgy9tB3ZbQob0R7Q= =ZNsX -----END PGP SIGNATURE-----