Cyber Resilience

CVE-2023-23931

MediumPublic PoC

Published: 07 February 2023

Published
07 February 2023
Modified
03 November 2025
KEV Added
Patch
CVSS Score v3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
EPSS Score 0.0069 72.2th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-23931 is a medium-severity Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability in Cryptography.Io Cryptography. Its CVSS base score is 4.8 (Medium).

Operationally, ranked in the top 27.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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`)…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cryptography.io
cryptography
1.8 — 39.0.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-754

Requires detection and response to audit logging failures as an unusual or exceptional condition.

addresses: CWE-754

Implements detection of unusual or exceptional conditions followed by safe mode entry, reducing the window for exploitation of unchecked conditions.

addresses: CWE-754

Training ensures users perform required checks for unusual or exceptional conditions as part of contingency roles, limiting attacker leverage from skipped validations.

addresses: CWE-754

IR testing directly validates checks for unusual or exceptional conditions that could indicate security incidents.

addresses: CWE-754

Requires ongoing monitoring of organization-defined metrics and analysis, enabling checks for unusual or exceptional conditions.

addresses: CWE-754

Security testing routinely checks for unusual or exceptional inputs/conditions, identifying missing validation steps that flaw remediation then resolves.

addresses: CWE-754

Requires detection of unusual conditions followed by a controlled transition to the defined failure state.

addresses: CWE-754

MTTF determination forces explicit checks for conditions that precede predictable component failure.

References