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CVE-2011-1521

MEDIUM severity · CVSS 6.4 · CWE-399
6.4CVSS MEDIUM

Summary

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.

Impact & exploitability

Attack vectorNetwork
Attack complexityLow
Privileges required
User interaction
Confidentiality impact
Integrity impactNone
Availability impact
Exploit probability (EPSS)1%

AV:N/AC:L/Au:N/C:P/I:N/A:P

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: http://bugs.python.org/issue11662 ↗

Last checked: Wed, 10 Jun 2026 22:18:30 UTC