Description of problem: The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage. Version-Release number of selected component (if applicable): All versions between >=1.9.0 and <2.3 * python-cryptography-2.0.2-4.fc27 * python-cryptography-2.2.1-1.fc28 * python-cryptography-2.2.1-3.fc29 EL7 only contains python-cryptography-1.7.2-1.el7_4.1, so it's not affected. How reproducible: always Additional info: The issue was fixed by PR https://github.com/pyca/cryptography/pull/4342 and in upstream release 2.3 (released today). The security issue is already public knowledge.
python-cryptography-2.3-1.fc28 python-cryptography-vectors-2.3-1.fc28 has been submitted as an update to Fedora 28. https://bodhi.fedoraproject.org/updates/FEDORA-2018-a9fe5e183e
python-cryptography-2.3-1.fc27 python-cryptography-vectors-2.3-1.fc27 has been submitted as an update to Fedora 27. https://bodhi.fedoraproject.org/updates/FEDORA-2018-06c24068c6
python-cryptography-2.3-1.fc27, python-cryptography-vectors-2.3-1.fc27 has been pushed to the Fedora 27 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-06c24068c6
python-cryptography-2.3-1.fc28, python-cryptography-vectors-2.3-1.fc28 has been pushed to the Fedora 28 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-a9fe5e183e
python-cryptography-2.3-1.fc28, python-cryptography-vectors-2.3-1.fc28 has been pushed to the Fedora 28 stable repository. If problems still persist, please make note of it in this bug report.
python-cryptography-2.3-1.fc27, python-cryptography-vectors-2.3-1.fc27 has been pushed to the Fedora 27 stable repository. If problems still persist, please make note of it in this bug report.