The urllib and urllib2 modules in Python 2.x before 2.7.2 and 3.x before 3.2.1 process Location headers that specify redirection to file: URLs, which makes it easier for remote attackers to obtain sensitive information or cause a denial of service (resource consumption) via a crafted URL, as demonstrated by the file:///etc/passwd and file:///dev/zero URLs.

References

• https://nvd.nist.gov/vuln/detail/CVE-2011-1521
• https://bugzilla.redhat.com/show_bug.cgi?id=690560
• https://bugzilla.redhat.com/show_bug.cgi?id=737366
• https://www.djangoproject.com/weblog/2011/sep/09/
• https://www.djangoproject.com/weblog/2011/sep/10/127/
• http://bugs.python.org/issue11662
• http://hg.python.org/cpython/file/96a6c128822b/Misc/NEWS
• http://hg.python.org/cpython/file/b2934d98dac1/Misc/NEWS
• http://hg.python.org/cpython/rev/96a6c128822b/
• http://hg.python.org/cpython/rev/b2934d98dac1/
• http://lists.apple.com/archives/Security-announce/2011//Oct/msg00003.html
• http://lists.opensuse.org/opensuse-security-announce/2011-05/msg00005.html
• http://openwall.com/lists/oss-security/2011/03/24/5
• http://openwall.com/lists/oss-security/2011/03/28/2
• http://openwall.com/lists/oss-security/2011/09/11/1
• http://openwall.com/lists/oss-security/2011/09/13/2
• http://openwall.com/lists/oss-security/2011/09/15/5
• http://secunia.com/advisories/50858
• http://secunia.com/advisories/51024
• http://secunia.com/advisories/51040
• http://securitytracker.com/id?1025488
• http://support.apple.com/kb/HT5002
• http://www.mandriva.com/security/advisories?name=MDVSA-2011:096
• http://www.ubuntu.com/usn/USN-1592-1
• http://www.ubuntu.com/usn/USN-1596-1
• http://www.ubuntu.com/usn/USN-1613-1
• http://www.ubuntu.com/usn/USN-1613-2