Require execute permission on the trigger function for CREATE TRIGGER.
This check was overlooked when we added function execute permissions to the
system years ago. For an ordinary trigger function it's not a big deal,
since trigger functions execute with the permissions of the table owner,
so they couldn't do anything the user issuing the CREATE TRIGGER couldn't
have done anyway. However, if a trigger function is SECURITY DEFINER,
that is not the case. The lack of checking would allow another user to
install it on his own table and then invoke it with, essentially, forged
input data; which the trigger function is unlikely to realize, so it might
do something undesirable, for instance insert false entries in an audit log
table.
Reported by Dinesh Kumar, patch by Robert Haas
Security: CVE-2012-0866
Branch
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REL9_1_STABLE
Details
-------
http://git.postgresql.org/pg/commitdiff/54e2b6488bb294691a525a272d6f614ac2046282
Modified Files
--------------
doc/src/sgml/ref/create_trigger.sgml | 3 ++-
src/backend/commands/trigger.c | 11 +++++++++--
2 files changed, 11 insertions(+), 3 deletions(-)