CERT Advisory CA-95:05, available via FTP from info.cert.org, states
There is a problem in versions of sendmail that support IDENT (RFC 1413) functionality. This problem could allow an intruder to gain unauthorized access to your system remotely (that is, without having access to an account on the system)
Sendmail version 8.6.10 is not vulnerable. This version is available by anonymous FTP from ftp.cs.berkeley.edu:/ucb/sendmail ftp.uu.net:/networking/mail/sendmail/UCB info.cert.org:/pub/tools/sendmail/sendmail.8.6.10 ftp.cert.dfn.de:/pub/tools/net/sendmail ftp.auscert.org.au:/pub/coast/mirrors/ftp.cs.berkeley.edu/ucb/sendmail In all of the above locations, the MD5 checksums are the same, MD5 (sendmail.8.6.10.base.tar.Z) = 4ab8ac267b1eaf8d1725c14cf4b2e885 MD5 (sendmail.8.6.10.cf.tar.Z) = c70c576697bbbf047ed379a7b98633f6 MD5 (sendmail.8.6.10.misc.tar.Z) = 6212390ca0bb4b353e29521f1aab492f MD5 (sendmail.8.6.10.patch) = 08d6f977c171ea858f1e940163212c3a MD5 (sendmail.8.6.10.xdoc.tar.Z) = 8b2252943f365f303b6302b71ef9a841