Multiple shell programs on various Unix systems, including (1) tcsh, (2) csh, (3) sh, and (4) bash, follow symlinks when processing << redirects (aka here-documents or in-here documents), which allows local users to overwrite files of other users via a symlink attack.
ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-00:76.tcsh-csh.asc
ftp://patches.sgi.com/support/free/security/advisories/20011103-02-P
archives.neohapsis.com/archives/bugtraq/2000-10/0418.html
archives.neohapsis.com/archives/tru64/2002-q1/0009.html
distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000350
distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000354
marc.info/?l=bugtraq&m=97561816504170&w=2
www.calderasystems.com/support/security/advisories/CSSA-2000-042.0.txt
www.calderasystems.com/support/security/advisories/CSSA-2000-043.0.txt
www.debian.org/security/2000/20001111a
www.kb.cert.org/vuls/id/10277
www.linux-mandrake.com/en/security/MDKSA-2000-069.php3
www.linux-mandrake.com/en/security/MDKSA-2000-075.php3
www.redhat.com/support/errata/RHSA-2000-117.html
www.redhat.com/support/errata/RHSA-2000-121.html
www.securityfocus.com/archive/1/146657
www.securityfocus.com/bid/1926
www.securityfocus.com/bid/2006
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A4047