CVE-2018-10903
PyCA Cryptography vulnerable to GCM tag forgery
7.5
HIGH
CVSS 3.1
EPSS 0.24%
Description
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.
How to fix CVE-2018-10903
To remediate CVE-2018-10903, upgrade the affected package to a fixed version below.
- —upgrade to 2.3-1 or later
- —upgrade to 2.3 or later
- —upgrade to 2.3 or later
Is CVE-2018-10903 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 2.3-1
- >= 1.9.0, < 2.3
- >= 1.9, < 2.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |