CVE-2018-6594 Pycrypto generates weak key parameters

What is CVE-2018-6594?

CVE-2018-6594 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 3 Feb 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-326

Which versions are affected by CVE-2018-6594?

3 open source packages ship an affected version, including pycrypto. It affects 3 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Dlitz Pycrypto.

How do I fix CVE-2018-6594?

Upgrade to a fixed version.

Is CVE-2018-6594 being exploited?

There is no known exploitation of CVE-2018-6594 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2018-6594, GHSA-6528-wvf6-f6qg, MGASA-2018-0171, PYSEC-2018-97, UBUNTU-CVE-2018-6594, USN-3616-1.