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Fencer Intel
medium 6.4

CVE-2011-1521 json

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: U…

published 2011-05-24 15 y ago modified 2026-06-16 4 mo ago also EUVD-2011-1522

cvss
6.4
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.6%
EPSS 3.6% chance of exploitation in 30 days, percentile 89%
public exploits
0
none known

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.

Patch / fix

  • python2.7 Debian 11 2.7.1-7

debian advisories DEBIAN-CVE-2011-1521

  • python RHEL 6 2.6.6-20.el6
  • tkinter RHEL 6 2.6.6-20.el6
  • python-libs RHEL 6 2.6.6-20.el6
  • python-test RHEL 6 2.6.6-20.el6
  • python-tools RHEL 6 2.6.6-20.el6
  • python RHEL 5 2.4.3-44.el5
  • tkinter RHEL 5 2.4.3-44.el5
  • python-libs RHEL 5 2.4.3-44.el5

red hat advisories RHSA-2011:0554RHSA-2011:0492RHSA-2011:0491

  • python SLE Module for Python 2 15 SP1, SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 +2 more 2.7.17-7.32.2
  • python-base SLE Module for Python 2 15 SP1, SLE Module for Basesystem 15 SP1, SLE Module for Basesystem 15 2.7.17-7.32.1

suse advisories SUSE-SU-2020:0234-1

  • python-base openSUSE Tumbleweed 2.7.12-1.4
  • python openSUSE Tumbleweed 2.7.18-8.1

opensuse advisories openSUSE-SU-2024:10536-1openSUSE-SU-2024:11202-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2011-1521 updated cvss 6.4

urllib2): Improper management of ftp:// and file:// URL schemes (Issue #11662)

  • Red Hat Enterprise Linux (v. 5 server) python 2.4.3-44.el5, tkinter 2.4.3-44.el5, python-libs 2.4.3-44.el5, python-tools 2.4.3-44.el5
    fixed: vendor fix RHSA-2011:0492
  • Red Hat Enterprise Linux AS version 4 python 2.3.4-14.10.el4, tkinter 2.3.4-14.10.el4, python-tools 2.3.4-14.10.el4
    fixed: vendor fix RHSA-2011:0491
  • Red Hat Enterprise Linux Desktop (v. 5 client) python 2.4.3-44.el5, tkinter 2.4.3-44.el5, python-libs 2.4.3-44.el5, python-tools 2.4.3-44.el5
    fixed: vendor fix RHSA-2011:0492
  • Red Hat Enterprise Linux Desktop (v. 6) python 2.6.6-20.el6, tkinter 2.6.6-20.el6, python-libs 2.6.6-20.el6 Red Hat Enterprise Linux Desktop Optional (v. 6) python 2.6.6-20.el6, python-test 2.6.6-20.el6, python-tools 2.6.6-20.el6
    fixed: vendor fix RHSA-2011:0554
  • Red Hat Enterprise Linux Desktop version 4 python 2.3.4-14.10.el4, tkinter 2.3.4-14.10.el4, python-tools 2.3.4-14.10.el4
    fixed: vendor fix RHSA-2011:0491
  • Red Hat Enterprise Linux Desktop Workstation (v. 5 client) python 2.4.3-44.el5
    fixed: vendor fix RHSA-2011:0492
  • Red Hat Enterprise Linux ES version 4 python 2.3.4-14.10.el4, tkinter 2.3.4-14.10.el4, python-tools 2.3.4-14.10.el4
    fixed: vendor fix RHSA-2011:0491
  • Red Hat Enterprise Linux HPC Node (v. 6) python 2.6.6-20.el6, python-libs 2.6.6-20.el6 Red Hat Enterprise Linux HPC Node Optional (v. 6) python 2.6.6-20.el6, tkinter 2.6.6-20.el6, python-test 2.6.6-20.el6, python-tools 2.6.6-20.el6 Red Hat Enterprise Linux Server (v. 6) python 2.6.6-20.el6, tkinter 2.6.6-20.el6, python-libs 2.6.6-20.el6 Red Hat Enterprise Linux Server Optional (v. 6) python 2.6.6-20.el6, tkinter 2.6.6-20.el6, python-test 2.6.6-20.el6, python-tools 2.6.6-20.el6 Red Hat Enterprise Linux Workstation (v. 6) python 2.6.6-20.el6, tkinter 2.6.6-20.el6, python-libs 2.6.6-20.el6 Red Hat Enterprise Linux Workstation Optional (v. 6) python 2.6.6-20.el6, python-test 2.6.6-20.el6, python-tools 2.6.6-20.el6
    fixed: vendor fix RHSA-2011:0554
show 1 more
  • Red Hat Enterprise Linux WS version 4 python 2.3.4-14.10.el4, tkinter 2.3.4-14.10.el4, python-tools 2.3.4-14.10.el4
    fixed: vendor fix RHSA-2011:0491

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.56% chance of exploitation in the next 30 days, higher than 89% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:N/A:P

Classification

Weakness
  • CWE-399 Resource Management Errors

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.