Vulnerability Details CVE-2018-10903
A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 48.4%
CVSS Severity
CVSS v3 Score 7.5
CVSS v2 Score 5.0
References
- https://access.redhat.com/errata/RHSA-2018:3600
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10903
- https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef
- https://usn.ubuntu.com/3720-1/
- https://access.redhat.com/errata/RHSA-2018:3600
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10903
- https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef
- https://usn.ubuntu.com/3720-1/
Products affected by CVE-2018-10903
-
cpe:2.3:a:cryptography:python-cryptography:*
-
cpe:2.3:a:redhat:openstack:13
-
cpe:2.3:o:canonical:ubuntu_linux:18.04