Red Hat Bugzilla – Bug 1305437
CVE-2016-2217 socat: Hard coded 1024 bit DH p parameter was not prime
Last modified: 2016-11-08 10:56:19 EST
It was found that in the OpenSSL address implementation the hard coded 1024 bit DH p parameter was not prime. The effective cryptographic strength of a key exchange using these parameters was weaker than the one one could get by using a prime p, making easier for eavesdropper to recover the shared secret from a key exchange that uses them.
Affected versions are 126.96.36.199 and 2.0.0-b8.
why was this closed again? It is a real bug for which there is a bug fix
(In reply to Paul Wouters from comment #1)
> why was this closed again? It is a real bug for which there is a bug fix
Versions we ship are listed in advisory as not affected.
The problematic 1024 bit DH param was introduced in this commit in version 188.8.131.52:
socat versions in Red Hat Enterprise Linux 7 and Fedora / EPEL are all 1.7.2.x, and hence use 512 bit DH params by default. Of course, such short parameters are known to be too weak these days - see LOGJAM / bug 1223211 - and should be replaced. We've had Red Hat Enterprise Linux 7 bug 1021946 open for that for a while now. Users of socat can use dhparams or cert options for OPENSSL address type to make it use custom stronger DH parameters.
Upstream security advisory link follows.