CVE-2016-9243

high

Description

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

References

Advisories
More

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL/

https://github.com/pyca/cryptography/issues/3211

https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2d874

https://cryptography.io/en/latest/changelog

http://www.ubuntu.com/usn/USN-3138-1

http://www.openwall.com/lists/oss-security/2016/11/09/2

Details

Source: Mitre, NVD

Published: 2017-03-27

Updated: 2025-04-20

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.01644