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Fencer Vulns
high 7.5

CVE-2021-33571 json

Django Access Control Bypass possibly leading to SSRF, RFI, and LFI attacks

published 2021-06-08 5 y ago modified 2026-09-08 2 mo ago also BIT-django-2021-33571 , EUVD-2021-0068 , GHSA-p99v-5w3c-jqq9 , PYSEC-2021-99

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.3%
EPSS 5.3% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+..) .

Patch / fix

  • pypi django 2.2.24, 3.1.12, 3.2.4
  • bitnami django 2.2.24, 3.1.12, 3.2.4
  • djangoproject django 2.2.24, 3.1.12, 3.2.4
  • python-django Debian 14, Debian 13, Debian 12 2:2.2.24-1

debian advisories DEBIAN-CVE-2021-33571

  • python-django Ubuntu 20.04 LTS 2:2.2.12-1ubuntu0.7

ubuntu advisories UBUNTU-CVE-2021-33571

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • foreman satellite capsule 6.10, satellite 6.10 2.5.2.17-2.el7sat
  • candlepin satellite 6.10 4.0.9-1.el7sat
  • satellite satellite capsule 6.10, satellite 6.10 6.10.0-3.el7sat
  • python-ecdsa satellite capsule 6.10, satellite 6.10 0.13.3-2.el7pc
  • python-pyyaml satellite capsule 6.10, satellite 6.10 5.4.1-1.el7pc
  • python3-ecdsa satellite capsule 6.10, satellite 6.10 0.13.3-2.el7pc
  • python-aiohttp satellite capsule 6.10, satellite 6.10 3.7.4-1.el7pc
  • python-urllib3 satellite capsule 6.10, satellite 6.10 1.26.5-1.el7pc

red hat advisories RHSA-2021:4702RHSA-2021:5070RHSA-2021:3490

  • kibana OpenStack Cloud Crowbar 8, OpenStack Cloud 8, HPE Helion OpenStack 8 4.6.6-3.9.2
  • grafana OpenStack Cloud Crowbar 8, OpenStack Cloud 8, HPE Helion OpenStack 8 6.7.4-4.18.2
  • cassandra OpenStack Cloud Crowbar 8, OpenStack Cloud 8, HPE Helion OpenStack 8 3.11.10-5.3.5
  • python-py OpenStack Cloud Crowbar 8, OpenStack Cloud 8, HPE Helion OpenStack 8 1.4.34-3.3.3
  • crowbar-core OpenStack Cloud Crowbar 8 5.0+git.1622489449.a8e60e238-3.50.4
  • python-Django OpenStack Cloud Crowbar 8, OpenStack Cloud 8, HPE Helion OpenStack 8 1.11.29-3.25.3
  • ardana-cobbler OpenStack Cloud 8, HPE Helion OpenStack 8 8.0+git.1614096566.e8c2b27-3.44.3
  • openstack-nova OpenStack Cloud Crowbar 8, OpenStack Cloud 8, HPE Helion OpenStack 8 16.1.9~dev92-3.48.5

suse advisories SUSE-SU-2021:2554-1SUSE-SU-2021:1963-1SUSE-SU-2021:1962-1

  • python-Django5 openSUSE Tumbleweed 5.2.16-1.1
  • python-Django openSUSE Tumbleweed 5.2.16-1.1
  • python-Django4 openSUSE Tumbleweed 4.2.30-4.1
  • python-Django6 openSUSE Tumbleweed 6.0-1.1
  • python-Django4 openSUSE Tumbleweed 4.2.14-1.1
  • python-Django openSUSE Tumbleweed 3.2.7-2.3
  • python-Django openSUSE Tumbleweed 4.2.11-2.1
  • python-Django Package Hub 15 SP3, openSUSE Leap 15.3 2.2.28-bp153.2.3.1

opensuse advisories openSUSE-SU-2026:11270-1openSUSE-SU-2026:11248-1openSUSE-SU-2026:11235-1openSUSE-SU-2026:10005-1openSUSE-SU-2024:14208-1openSUSE-SU-2024:11205-1

  • py3-django Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 3.1.13-r0

alpine advisories ALPINE-CVE-2021-33571

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-django Arch Linux 3.2.4-1

arch linux advisories AVG-2026

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-2021-33571 updated cvss 7.5

django: Possible indeterminate SSRF, RFI, and LFI attacks since validators accepted leading zeros in IPv4 addresses

  • Red Hat Ansible Automation Platform 1.2 django, python-django
    affected: workaround, no fix available
  • Red Hat Ansible Tower 3 django Red Hat Ceph Storage 2 python-django, calamari-server, python-django-bash-completion Red Hat Ceph Storage 3 python-django, python-django-bash-completion Red Hat OpenStack Platform 10 (Newton) python-django, python-django-bash-completion
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenStack Platform 13 (Queens) python-django, python2-django, python-django-bash-completion Red Hat Satellite 6 python-django, python2-django, python-django-bash-completion Red Hat Storage 3 python-django, python2-django, python-django-bash-completion Red Hat Update Infrastructure 3 for Cloud Providers python-django
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OpenStack Platform 16.1 python-django20 2.0.13-16.el8ost.1, python3-django20 2.0.13-16.el8ost.1, python-django20-bash-completion 2.0.13-16.el8ost.1
    fixed: vendor fix RHSA-2021:5070
  • Red Hat OpenStack Platform 16.2 python-django20 2.0.13-16.el8ost.1, python3-django20 2.0.13-16.el8ost.1
    fixed: vendor fix RHSA-2021:3490
  • Red Hat Satellite 6.10 python3-django 2.2.24-1.el7pc Red Hat Satellite Capsule 6.10 python3-django 2.2.24-1.el7pc
    fixed: vendor fix RHSA-2021:4702
  • Red Hat Satellite 6.10 tfm 7.0-1.el7sat, gofer 2.12.5-7.el7sat, katello 4.1.1-2.el7sat, libsolv 0.7.20-1.el7pc, receptor 0.6.4-2.el7ar, libcomps 0.1.15-1.el7pc, +581 more Red Hat Satellite Capsule 6.10 tfm 7.0-1.el7sat, katello 4.1.1-2.el7sat, libsolv 0.7.20-1.el7pc, libcomps 0.1.15-1.el7pc, python-rq 1.8.1-1.el7pc, python-idna 2.10-1.el7pc, +354 more
    not affected: vulnerable code not present

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

5.26% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi django
>=2.2a1, <2.2.24
>=3.0a1, <3.1.12
>=3.2a1, <3.2.4
>=2.2, <2.2.24
>=3.0, <3.1.12
>=3.2, <3.2.4
2.2.24
3.1.12
3.2.4
bitnami django
>=2.2.0, <2.2.24
>=3.0.0, <3.1.12
>=3.2.0, <3.2.4
2.2.24
3.1.12
3.2.4

Classification

Weakness
  • CWE-918 Server-Side Request Forgery
Technology feeds

References

Sources

Fencer Vulns 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.