Horton

Re: Schema Usage Patterns vs. dbowner or CREATEROLE

Noah Misch <noah@leadboat.com>

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From: Noah Misch <noah@leadboat.com>
To: pgsql-docs@postgresql.org
Date: 2019-12-01T22:38:49Z
Lists: pgsql-docs

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On Sat, Oct 12, 2019 at 06:35:12PM -0700, Noah Misch wrote:
> When I updated
> https://www.postgresql.org/docs/devel/ddl-schemas.html#DDL-SCHEMAS-PATTERNS
> for CVE-2018-1058, I wrote that some schema usage patterns are secure against
> CREATEROLE users and database owners.  That was incorrect.  Even with the
> first pattern, a database owner can attack the database's users via "CREATE
> SCHEMA trojan; ALTER DATABASE $mydb SET search_path = trojan, public;".  A
> CREATEROLE user can issue "GRANT $dbowner TO $me" and then use the database
> owner attack.  I plan to update this section to assert that all three usage
> patterns are equally vulnerable to dbowner and CREATEROLE attack.  (The
> technique described under "If untrusted users have access to a database ..."
> in libpq.sgml remains secure.)

I'm attaching a patch for that.  Two of the patterns became so similar that I
merged them.

Commits

  1. Document search_path security with untrusted dbowner or CREATEROLE.