CVE-2018-6594

Publication date 3 February 2018

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

lib/Crypto/PublicKey/ElGamal.py in PyCrypto through 2.6.1 generates weak ElGamal key parameters, which allows attackers to obtain sensitive information by reading ciphertext data (i.e., it does not have semantic security in face of a ciphertext-only attack). The Decisional Diffie-Hellman (DDH) assumption does not hold for PyCrypto's ElGamal implementation.

Status

Package Ubuntu Release Status
pycryptodome 18.04 LTS bionic
Fixed 3.4.7-1ubuntu1
17.10 artful Ignored end of life
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
python-crypto 18.04 LTS bionic
Fixed 2.6.1-8ubuntu2
17.10 artful
Fixed 2.6.1-7ubuntu0.1
16.04 LTS xenial
Fixed 2.6.1-6ubuntu0.16.04.3
14.04 LTS trusty
Fixed 2.6.1-4ubuntu0.3

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
pycryptodome
python-crypto

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact None
Availability impact None
Vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

    • USN-3616-1
    • Python Crypto vulnerability
    • 3 April 2018
    • USN-3616-2
    • Python Crypto vulnerability
    • 9 April 2018

Other references