CVE-2021-29921
CRITICAL severity · CVSS 9.8
9.8CVSS CRITICAL
Summary
In Python before 3,9,5, the ipaddress library mishandles leading zero characters in the octets of an IP address string. This (in some situations) allows attackers to bypass access control that is based on IP addresses.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)7%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://bugs.python.org/issue36384 ↗
Additional information
- NVD record
- https://bugs.python.org/issue36384Patch
- https://github.com/python/cpython/pull/12577Patch
- https://github.com/python/cpython/pull/25099Patch
- https://docs.python.org/3/library/ipaddress.htmlAdvisory
- https://python-security.readthedocs.io/vuln/ipaddress-ipv4-leading-zeros.htmlAdvisory
- https://github.com/python/cpython/blob/63298930fb531ba2bb4f23bc3b915dbf1e17e9e1/Misc/NEWS.d/3.8.0a4.rstAdvisory
- https://github.com/sickcodesAdvisory
- https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-014.mdAdvisory