CVSS 3.0
7.5 highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NCVE-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.
Severity
- EPSS
- 3.2% chance of exploitation in the next 30 days; higher than 88% of CVEs (scores of 2026-10-31)
- CWE
- CWE-20
- Published
- Modified
- Record from
- the NVD, synced
Affected
- canonical:ubuntu_linux
- cryptography:python-cryptography
- redhat:openstack
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-fcf9-3qw3-gxmj | PyPI | cryptography | >=1.9.0 <2.3 | 2.3 |
| PYSEC-2018-52 | PyPI | cryptography | >=1.9 <2.3 | 2.3 |