|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.|
|Source||CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)|
|NVD severity||medium (attack range: remote)|
|Debian Bugs||889998, 889999|
Vulnerable and fixed packages
The table below lists information on source packages.
|pycryptodome (PTS)||buster, sid||3.6.1-2||fixed|
The information below is based on the following data on fixed versions.
[stretch] - python-crypto <no-dsa> (Minor issue)
[jessie] - python-crypto <no-dsa> (Minor issue)
[wheezy] - python-crypto <no-dsa> (Minor issue)
The issue is found as well in pycryptodome (fork from python-crypto)
PyCrytpodome: https://github.com/Legrandin/pycryptodome/commit/99c27a3b9e8a884bbde0e88c63234b669d4398d8 (3.4.10)
See further discussion as per https://github.com/Legrandin/pycryptodome/issues/90#issuecomment-362783537
Upstream feels that this is not a vulnerability in pycryptodome/python-crypto,
but in an application using it in an insecure manner.