Cipher.update_into can corrupt memory in pyca cryptography
Priority MEDIUM 62CWE-754Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · Low
- Fix status
- Partial Red Hat: 9 fixed, 6 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat.
Summary
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In affected versions `Cipher.update_into` would accept Python objects which implement the buffer protocol, but provide only immutable buffers. This would allow immutable objects (such as `bytes`) to be mutated, thus violating fundamental rules of Python and resulting in corrupted output. This now correctly raises an exception. This issue has been present since `update_into` was originally introduced in cryptography 1.8.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01301 70th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial cryptography (pyca): 39.0.1cryptography (PyPI): 39.0.1Red Hat: 7 advisoriesRed Hat: 9 fixed, 6 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| pyca | cryptography | 1.8 to before 39.0.1 | 39.0.1 | Patch available | CNA |
| — | cryptography (PyPI) | 1.8 to before 39.0.1 | 39.0.1 | Patch available | GHSA-w7pp-m8wf-vj6r |
- cryptography Vendorpyca Affected 1.8 to before 39.0.1 Fixed in 39.0.1 Patch available CNA
- cryptography (PyPI) Vendor— Affected 1.8 to before 39.0.1 Fixed in 39.0.1 Patch available GHSA-w7pp-m8wf-vj6r
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:cryptography.io:cryptography:*:*:*:*:*:python:*:* | 1.8 to before 39.0.1 | Vulnerable | Cryptography.io |
- cpe:2.3:a:cryptography.io:cryptography:*:*:*:*:*:python:*:* Versions 1.8 to before 39.0.1 Vulnerable ·Cryptography.io
Remediation
- Fix · CNA cryptography (pyca) Fixed in 39.0.1
- Fix · GHSA-w7pp-m8wf-vj6r cryptography (PyPI) Fixed in 39.0.1 Advisory →
Red Hat 7 advisories
- RHSA-2024:2985 Released 2024-05-22 · Red Hat rating Moderatepython39:3.9 and python39-devel:3.9 security update
- Red Hat Enterprise Linux AppStream (v. 8) PyYAML-5.4.1-1.module+el8.9.0+19644+d68f775d.src::python39:3.9, mod_wsgi-4.7.1-7.module+el8.9.0+19644+d68f775d.src::python39:3.9, numpy-1.19.4-3.module+el8.9.0+19644+d68f775d.src::python39:3.9 +47
- Red Hat Enterprise Linux CRB (v. 8) Cython-0.29.21-5.module+el8.9.0+19644+d68f775d.src::python39-devel:3.9, pybind11-2.7.1-1.module+el8.9.0+19644+d68f775d.src::python39-devel:3.9, pytest-6.0.2-2.module+el8.9.0+19644+d68f775d.src::python39-devel:3.9 +33
- RHSA-2023:7341 Released 2023-11-30 · Red Hat rating ImportantRed Hat Quay security update
- Quay v3 quay/quay-rhel8
- RHSA-2023:7096 Released 2023-11-14 · Red Hat rating Moderatepython-cryptography security update
- Red Hat Enterprise Linux BaseOS (v. 8) python-cryptography-3.2.1-6.el8, python3-cryptography-3.2.1-6.el8
Show 4 more Red Hat advisories
- RHSA-2023:6793 Released 2023-11-08 · Red Hat rating Importantrh-python38-python security update
- Red Hat Software Collections for RHEL Workstation(v. 7) rh-python38-python-3.8.18-2.el7, rh-python38-python-cryptography-2.8-6.el7, rh-python38-python-debug-3.8.18-2.el7 +14
- Red Hat Software Collections for RHEL(v. 7) rh-python38-python-3.8.18-2.el7, rh-python38-python-cryptography-2.8-6.el7, rh-python38-python-debug-3.8.18-2.el7 +14
- RHSA-2023:6615 Released 2023-11-07 · Red Hat rating Moderatepython-cryptography security update
- Red Hat Enterprise Linux BaseOS (v. 9) python-cryptography-36.0.1-4.el9, python3-cryptography-36.0.1-4.el9
- RHSA-2023:4971 Released 2023-09-05 · Red Hat rating ModerateRed Hat Ansible Automation Platform 2.4 Product Security and Bug Fix Update
- Red Hat Ansible Automation Platform 2.4 for RHEL 8 automation-controller-venv-tower-4.4.3-1.el8ap, python39-gitpython-3.1.32-1.el8ap, python3x-gitpython-3.1.32-1.el8ap
- Red Hat Ansible Automation Platform 2.4 for RHEL 9 automation-controller-venv-tower-4.4.3-1.el9ap, python-gitpython-3.1.32-1.el9ap, python3-gitpython-3.1.32-1.el9ap
- RHSA-2023:4693 Released 2023-08-21 · Red Hat rating ModerateRed Hat Ansible Automation Platform 2.4 Product Security and Bug Fix Update
- Red Hat Ansible Automation Platform 2.4 for RHEL 8 automation-eda-controller-1.0.1-1.el8ap, automation-eda-controller-server-1.0.1-1.el8ap, automation-eda-controller-ui-1.0.1-1.el8ap +6
- Red Hat Ansible Automation Platform 2.4 for RHEL 9 automation-eda-controller-1.0.1-1.el9ap, automation-eda-controller-server-1.0.1-1.el9ap, automation-eda-controller-ui-1.0.1-1.el9ap +4
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Discovery 1 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Will not fix |
| Red Hat OpenShift Data Science (RHODS) | Affected | No fix planned: Will not fix |
| Red Hat OpenStack Platform 13 (Queens) | Affected | No fix planned: Out of support scope |
| Red Hat Update Infrastructure 4 for Cloud Providers | Affected | No fix planned: Will not fix |
| Quay v3 | Fixed | RHSA-2023:7341 |
| Red Hat Ansible Automation Platform 2.4 for RHEL 8 | Fixed | RHSA-2023:4693, RHSA-2023:4971 |
| Red Hat Ansible Automation Platform 2.4 for RHEL 9 | Fixed | RHSA-2023:4693, RHSA-2023:4971 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2024:2985 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2023:7096 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2023:6615 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2024:2985 |
| Red Hat Software Collections for RHEL Workstation(v. 7) | Fixed | RHSA-2023:6793 |
| Red Hat Software Collections for RHEL(v. 7) | Fixed | RHSA-2023:6793 |
Not affected: 10 products
- Quay v3
- Red Hat Ansible Automation Platform 2
- Red Hat Ansible Automation Platform 2.4 for RHEL 8
- Red Hat Ansible Automation Platform 2.4 for RHEL 9
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat JBoss Enterprise Application Platform 7
- Red Hat JBoss Enterprise Application Platform Expansion Pack
- Red Hat Software Collections for RHEL Workstation(v. 7)
- Red Hat Software Collections for RHEL(v. 7)
Timeline
- 2026-10-02 Threatist record created from CVE-2023-23931
- 2026-10-03 Alias added: GHSA-w7pp-m8wf-vj6r
References
Patch 1
Other 6
- https://github.com/pyca/cryptography/pull/8230
- https://github.com/pyca/cryptography/commit/d6951dca25de45abd52da51b608055371fbcde4e
- https://github.com/pyca/cryptography
- https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2023-11.yaml
- https://lists.debian.org/debian-lts-announce/2024/10/msg00012.html
- https://security.netapp.com/advisory/ntap-20230324-0007
More pyca vulnerabilities
- TI-2026-48588 python-cryptography: Duplicate self-signed intermediates can cause exponential path-building CVSS 4.0HIGH 8.7
- TI-2026-48587 python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees CVSS 4.0MEDIUM 6.9
- TI-2026-48586 cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing CVSS 4.0HIGH 8.2
Sources
- CVE-2023-23931 · CVE Program
- CVE-2023-23931 · NVD
- FIRST EPSS
- GHSA-w7pp-m8wf-vj6r · GitHub Advisory Database · CC BY 4.0
- CVE-2023-23931 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences