CVE-2011-1521

Severity: medium (CVSS 6.4 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2011-05-24 · updated 2026-06-16
Weakness: CWE-399

Description

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.

Affected products

Python: 2.0, 2.0.1, 2.1, 2.1.1, 2.1.2, 2.1.3 (+33)

References

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

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