CVE-2016-9243

moderate-risk

Published 2017-03-27

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

Do I need to act?

1.7% chance of exploitation in next 30 days

EPSS score — moderate exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 7.5/10 High

NETWORK / LOW complexity

Cryptography

Fedora

Ubuntu Linux

Fedora

Fedoraproject Cryptography.Io Canonical

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

Broken Link http://www.securityfocus.com/bid/94216

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

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

Patch https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2...

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

Mailing List https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...

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

Broken Link http://www.securityfocus.com/bid/94216

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

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

Patch https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2...

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

Mailing List https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro...

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moderate-risk

Severity 26/34 · High

Exploitability 4/34 · Minimal

Exposure 13/34 · Low