CVEvulnerability
CVE-2018-10903
7.5 HIGH
Official page ↗
- Status
- Modified
- Published
- 2018-07-30
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.0 ([email protected])
- 7.5 HIGH — CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CVSS 3.0 ([email protected])
- 7.5 HIGH — CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CVSS 2.0 ([email protected])
- 5.0 MEDIUM — AV:N/AC:L/Au:N/C:P/I:N/A:N
- Weaknesses
- CWE-20
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.
Affected configurations
• cryptography python-cryptography (>= 1.9.0 < 2.3)
• redhat openstack 13
• canonical ubuntu linux 18.04
Related
Weakness · CWE (1)
- CWE-20 Improper Input Validation weakness
References
- https://access.redhat.com/errata/RHSA-2018:3600 access.redhat.com
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10903 Issue Tracking, Patch, Third Party Advisory
- https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef Patch, Third Party Advisory
- https://usn.ubuntu.com/3720-1/ Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:3600 access.redhat.com
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10903 Issue Tracking, Patch, Third Party Advisory
- https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef Patch, Third Party Advisory
- https://usn.ubuntu.com/3720-1/ Third Party Advisory