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Fencer Vulns
medium 5.3

CVE-2021-33430 json

NumPy Buffer Overflow (Disputed)

published 2021-12-17 4 y ago modified 2026-06-17 4 mo ago also GHSA-6p56-wp2h-9hxr , PYSEC-2021-854 , EUVD-2021-0150

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

A Buffer Overflow vulnerability exists in NumPy 1.9.x in the PyArray_NewFromDescr_int function of ctors.c when specifying arrays of large dimensions (over 32) from Python code, which could let a malicious user cause a Denial of Service. NOTE: The vendor does not agree this is a vulneraility; In (very limited) circumstances a user may be able provoke the buffer overflow, the user is most likely already privileged to at least provoke denial of service by exhausting memory. Triggering this further requires the use of uncommon API (complicated structured dtypes), which is very unlikely to be available to an unprivileged user

Patch / fix

  • pypi numpy 1.10.0, 1.21
  • numpy Debian 14, Debian 13, Debian 12 1:1.21.4-2

debian advisories DEBIAN-CVE-2021-33430

  • numpy Ubuntu 20.04 LTS 1:1.17.4-5ubuntu3.1

ubuntu advisories UBUNTU-CVE-2021-33430

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

  • numpy openstack 16.2, openstack 16.1 1:1.17.0-8.el8ost
  • python3-numpy openstack 16.2, openstack 16.1 1:1.17.0-8.el8ost
  • python3-numpy-f2py openstack 16.2, openstack 16.1 1:1.17.0-8.el8ost

red hat advisories RHSA-2022:0987RHSA-2022:1000

  • python-numpy SLES 15 SP2-BCL, SLES 15 SP1-BCL, SLE Real Time 15 SP2 +18 more 1.17.3-10.1
  • python-numpy_1_17_3-gnu-hpc SLE Real Time 15 SP2, SLE Module for HPC 15 SP3, SLE High Performance Computing 15-ESPOS +5 more 1.17.3-10.1
  • python2-numpy SLE Module for Python 2 15 SP3, SLE High Performance Computing 15 SP2-ESPOS, Manager Server 4.1 +6 more 1.16.5-150200.3.5.1
  • python-numpy_1_16_5-gnu-hpc SLE Module for HPC 15 SP3, SLE High Performance Computing 15 SP2-ESPOS, openSUSE Leap 15.4 +1 more 1.16.5-150200.3.5.1
  • python2-numpy SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 1.16.5-150000.1.9.1
  • python-numpy_1_16_5-gnu-hpc SLE High Performance Computing 15-LTSS, SLE High Performance Computing 15-ESPOS, SLE High Performance Computing 15 SP1-LTSS +1 more 1.16.5-150000.1.9.1
  • python-numpy_1_13_3-gnu-hpc SLE Module for HPC 12 1.13.3-4.12.1
  • python-numpy SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 1.8.0-5.11.1

suse advisories SUSE-SU-2022:0134-3SUSE-SU-2022:0134-2SUSE-SU-2022:0134-1SUSE-SU-2022:1064-2SUSE-SU-2022:1064-1SUSE-SU-2022:2441-1

  • python-numpy openSUSE Tumbleweed 2.4.6-1.1
  • python-numba openSUSE Tumbleweed 0.61.0-1.1
  • python-numpy1 openSUSE Tumbleweed 1.26.4-1.1
  • python-numpy openSUSE Tumbleweed 1.25.2-2.1
  • python-numpy openSUSE Leap 15.3 1.17.3-10.1
  • dxflib Package Hub 15 SP3, openSUSE Leap 15.3 3.17.0-bp153.2.3.1
  • python-numpy_1_17_3-gnu-hpc openSUSE Leap 15.3 1.17.3-10.1
  • python2-numpy openSUSE Leap 15.3 1.16.5-150200.3.5.1

opensuse advisories openSUSE-SU-2026:11371-1openSUSE-SU-2025:14743-1openSUSE-SU-2024:14311-1openSUSE-SU-2024:13220-1openSUSE-SU-2022:0134-1openSUSE-SU-2022:1064-1

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-2021-33430 updated cvss 7.5

numpy: buffer overflow in the PyArray_NewFromDescr_int() in ctors.c

  • Red Hat Enterprise Linux 8 numpy, python3-numpy, python3-numpy-f2py
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 9 python3-numpy, python3-numpy-f2py
    affected: no fix available
  • Red Hat OpenStack Platform 13 (Queens) python2-numpy, python2-numpy-f2py
    affected: no fix planned “Out of support scope”
  • Red Hat Software Collections rh-python38-python-numpy, rh-python38-python-numpy-f2py
    affected: no fix planned “Will not fix”
  • Red Hat OpenStack Platform 16.1 numpy 1.17.0-8.el8ost, python3-numpy 1.17.0-8.el8ost, python3-numpy-f2py 1.17.0-8.el8ost
    fixed: vendor fix RHSA-2022:0987
  • Red Hat OpenStack Platform 16.2 numpy 1.17.0-8.el8ost, python3-numpy 1.17.0-8.el8ost, python3-numpy-f2py 1.17.0-8.el8ost
    fixed: vendor fix RHSA-2022:1000
  • Red Hat Enterprise Linux 6 numpy, numpy-f2py Red Hat Enterprise Linux 7 numpy, numpy-f2py Red Hat Software Collections python27-numpy, python27-numpy-f2py
    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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

1.53% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/numpy/numpy/issues/18939 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:N/A:P
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi numpy
>=1.9.0, <1.21
>=1.9.0, <1.10.0
1.21
1.10.0

Classification

Weakness
  • CWE-120 Buffer Copy without Checking Size of Input

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.