Is CVE-2016-9243 actively exploited?

CVE-2016-9243 has no public evidence of in-the-wild exploitation as of 2025-04-20.

What is the CVSS score for CVE-2016-9243?

CVE-2016-9243 has a CVSS score of 7.5 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

How do I patch CVE-2016-9243?

Patch guidance is available from cryptography.io security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2016-9243.

Fix CVE-2016-9243 - HIGH cryptography.io cryptography

Q: Which products are affected by CVE-2016-9243?

6 products: cryptography.io cryptography, fedoraproject fedora, fedoraproject fedora, fedoraproject fedora, canonical ubuntu linux, and 1 more.

Description

HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: none
Integrity: high
Availability: none
Weaknesses: NVD-CWE-noinfo

Metadata

Primary Vendor: CRYPTOGRAPHY.IO
Published: 3/27/2017
Last Modified: 4/20/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

cryptography.io : cryptographyfedoraproject : fedorafedoraproject : fedorafedoraproject : fedoracanonical : ubuntu_linuxcanonical : ubuntu_linux

Remediation Guidance

Executive Summary

View on NIST NVD