CVE-2016-9243

Advisory

Cryptography 1.5.3 includes a fix for 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.
https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2d874

Affected package

Affected versions

Fixed versions

Vulnerability changelog

~~~~~~~~~~~~~~~~~~

* **SECURITY ISSUE**: Fixed a bug where ``HKDF`` would return an empty
byte-string if used with a ``length`` less than ``algorithm.digest_size``.
Credit to **Markus Döring** for reporting the issue. *CVE-2016-9243*

Resources

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9243
• https://lists.fedoraproject.org/archives/list/[email protected]/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ/
• https://lists.fedoraproject.org/archives/list/[email protected]/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.securityfocus.com/bid/94216
• http://www.openwall.com/lists/oss-security/2016/11/09/2