UBUNTU-CVE-2018-10903

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Source
https://ubuntu.com/security/CVE-2018-10903
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-10903.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2018-10903
Upstream
Downstream
Related
Published
2018-07-20T00:00:00Z
Modified
2025-07-16T07:51:54.865781Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
  • 7.5 (High) CVSS_V3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalizewithtag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalizewithtag 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.

References

Affected packages

Ubuntu:18.04:LTS / python-cryptography

Package

Name
python-cryptography
Purl
pkg:deb/ubuntu/python-cryptography@2.1.4-1ubuntu1.2?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.1.4-1ubuntu1.2

Affected versions

1.*

1.9-1

2.*

2.1.3-3
2.1.4-1
2.1.4-1build1
2.1.4-1build2
2.1.4-1ubuntu1
2.1.4-1ubuntu1.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "python-cryptography",
            "binary_version": "2.1.4-1ubuntu1.2"
        },
        {
            "binary_name": "python-cryptography-dbgsym",
            "binary_version": "2.1.4-1ubuntu1.2"
        },
        {
            "binary_name": "python-cryptography-doc",
            "binary_version": "2.1.4-1ubuntu1.2"
        },
        {
            "binary_name": "python3-cryptography",
            "binary_version": "2.1.4-1ubuntu1.2"
        },
        {
            "binary_name": "python3-cryptography-dbgsym",
            "binary_version": "2.1.4-1ubuntu1.2"
        }
    ]
}