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

CVE-2016-9243

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

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

HIGH · CVSS 7.5 EPSS 0.0165
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
▤

Affected Products & Versions

3
cryptography.io cryptography<= 1.5.2
fedoraproject fedoraall versions
canonical ubuntu linuxall versions
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
PyPI cryptography HIGH fixed in 1.5.3
▣

Scoring & Timeline

7.5
HIGH · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD27 Mar 2017 · 05:59 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
⚑

Vendor Advisories

1
usnUSN-3138-1
🔗

References & Sources

9
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
http://www.openwall.com/lists/oss-security/2016/11/09/2Mailing ListPatchVDB Entry
http://www.securityfocus.com/bid/94216Broken LinkThird Party AdvisoryVDB Entry
http://www.ubuntu.com/usn/USN-3138-1Third Party Advisory
https://cryptography.io/en/latest/changelogRelease NotesThird Party Advisory
https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2d874PatchThird Party Advisory
https://github.com/pyca/cryptography/issues/3211Issue TrackingThird Party Advisory
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