CVE-2021-33571
This may allow a bypass of access control that is based on IP addresses.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (5.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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+..) .
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 5.26% probability · 92th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- djangoproject/django · fedoraproject/fedora
- Source
- cve@mitre.org
EPSS 5.3% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://docs.djangoproject.com/en/3.2/releases/security/Patch, Vendor Advisory
- https://github.com/django/django/commit/203d4ab9ebcd72fc4d6eb7398e66ed9e474e118e
- https://github.com/django/django/commit/9f75e2e562fa0c0482f3dde6fc7399a9070b4a3d
- https://github.com/django/django/commit/f27c38ab5d90f68c9dd60cabef248a570c0be8fc
- https://groups.google.com/g/django-announce/c/sPyjSKMi8EoMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B4SQG2EAF4WCI2SLRL6XRDJ3RPK3ZRDV/
- https://security.netapp.com/advisory/ntap-20210727-0004/Third Party Advisory
- https://www.djangoproject.com/weblog/2021/jun/02/security-releases/Patch, Vendor Advisory
- https://docs.djangoproject.com/en/3.2/releases/security/Patch, Vendor Advisory
- https://github.com/django/django/commit/203d4ab9ebcd72fc4d6eb7398e66ed9e474e118e
- https://github.com/django/django/commit/9f75e2e562fa0c0482f3dde6fc7399a9070b4a3d
- https://github.com/django/django/commit/f27c38ab5d90f68c9dd60cabef248a570c0be8fc
- https://groups.google.com/g/django-announce/c/sPyjSKMi8EoMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B4SQG2EAF4WCI2SLRL6XRDJ3RPK3ZRDV/
- https://security.netapp.com/advisory/ntap-20210727-0004/Third Party Advisory
- https://www.djangoproject.com/weblog/2021/jun/02/security-releases/Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.