CVE-2018-6594

Name: CVE-2018-6594
Creator: NVD / NIST
Published: 2018-02-03T15:29:00.653+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 2.11%

Last modified Jun 17, 2026

CVE-2018-6594 is a vulnerability of currently unknown severity. 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.. EPSS estimates a 2.11% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability

2.11%

79.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-326

Affected Software

Vendor	Product	Versions
Dlitz	Pycrypto	<= 2.6.1
Debian	Debian Linux	7.0
Canonical	Ubuntu Linux	12.04
Canonical	Ubuntu Linux	14.04
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	17.10

References

https://github.com/TElgamal/attack-on-pycrypto-elgamalThird Party Advisory
https://github.com/dlitz/pycrypto/issues/253Exploit, Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/02/msg00018.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202007-62
https://usn.ubuntu.com/3616-1/Third Party Advisory
https://usn.ubuntu.com/3616-2/Third Party Advisory
https://github.com/TElgamal/attack-on-pycrypto-elgamalThird Party Advisory
https://github.com/dlitz/pycrypto/issues/253Exploit, Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/02/msg00018.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202007-62
https://usn.ubuntu.com/3616-1/Third Party Advisory
https://usn.ubuntu.com/3616-2/Third Party Advisory

Timeline

Published: Feb 3, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-6594?

How severe is CVE-2018-6594?

Severity scoring for CVE-2018-6594 is pending analysis. The EPSS model estimates a 2.11% probability of exploitation in the next 30 days.

How do I fix CVE-2018-6594?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-6594?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST