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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2005.0366 -- Important: two new PostgreSQL security problems found 5 May 2005 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: PostgreSQL 7.3 to 8.0.2 Publisher: PostgreSQL Operating System: UNIX variants Windows Impact: Increased Privileges Denial of Service Access: Existing Account CVE Names: CAN-2005-1409 CAN-2005-1410 Original Bulletin: http://www.postgresql.org/about/news.315 Comment: In conjunction with SQL injection vulnerabilities, remote unauthenticated compromise may be possible. - --------------------------BEGIN INCLUDED TEXT-------------------- From: Tom Lane To: pgsql-announce Subject: IMPORTANT: two new PostgreSQL security problems found Two serious security errors have been found in PostgreSQL 7.3 and newer releases. These errors at least allow an unprivileged database user to crash the backend process, and may make it possible for an unprivileged user to gain the privileges of a database superuser. We are currently preparing new releases that will correct these problems in freshly initdb'd installations. However, because these problems are really incorrect system catalog entries, updating to a new release will NOT by itself solve the problems in an existing installation. Instead, it is necessary for the database administrator to fix the catalog entries manually, as described below. We are releasing this advisory to encourage administrators of PostgreSQL installations to perform these fixes as soon as possible. Character conversion vulnerability - ---------------------------------- The more severe of the two errors is that the functions that support client-to-server character set conversion can be called from SQL commands by unprivileged users, but these functions are not designed to be safe against malicious choices of argument values. This problem exists in PostgreSQL 7.3.* through 8.0.*. The recommended fix is to disable public EXECUTE access for these functions. This does not affect normal usage of the functions for character set conversion, but it will prevent misuse. To accomplish this change, execute the following SQL command as a superuser: UPDATE pg_proc SET proacl = '{=}' WHERE pronamespace = 11 AND pronargs = 5 AND proargtypes[2] = 'cstring'::regtype; In 7.3.* through 8.0.*, this should report having updated 90 rows. 7.4 and later will report a "WARNING: defaulting grantor to user ID 1" which can be ignored. The above command must be carried out in *each* database of an installation, including template1, and ideally including template0 as well. If you do not fix the template databases then any subsequently created databases will contain the same vulnerability. template1 can be fixed in the same way as any other database, but fixing template0 requires additional steps. First, from any database issue UPDATE pg_database SET datallowconn = true WHERE datname = 'template0'; Next connect to template0 and perform the pg_proc update. Finally, do - -- re-freeze template0: VACUUM FREEZE; - -- and protect it against future alterations: UPDATE pg_database SET datallowconn = false WHERE datname = 'template0'; tsearch2 vulnerability - ---------------------- The other error is that the contrib/tsearch2 module misdeclares several functions as returning type "internal" when they do not have any "internal" argument. This breaks the type safety of "internal" by allowing users to construct SQL commands that invoke other functions accepting "internal" arguments. The consequences of this have not been investigated in detail, but it is certainly at least possible to crash the backend. This error affects PostgreSQL 7.4 and later, but only if you have installed the contrib/tsearch2 module. The recommended fix is to change the misdeclared functions so that they accept an "internal" argument and therefore cannot be called directly from SQL commands. To do this, execute the following command as a superuser: UPDATE pg_proc SET proargtypes[0] = 'internal'::regtype WHERE oid IN ( 'dex_init(text)'::regprocedure, 'snb_en_init(text)'::regprocedure, 'snb_ru_init(text)'::regprocedure, 'spell_init(text)'::regprocedure, 'syn_init(text)'::regprocedure ); This should report 5 rows updated. (If it fails with a message like "function "dex_init(text)" does not exist", then either tsearch2 is not installed in this database, or you already did the update.) You will need to do this in *each* database in which you have installed tsearch2, including template1. You need not worry about template0, however, since it will certainly not contain tsearch2. If you frequently install tsearch2 in new databases, you will also want to modify the tsearch.sql script to declare these functions as taking type internal in the first place. (The script fix will be part of the upcoming releases, so you may be able to wait for those.) On behalf of the PostgreSQL core committee, I'd like to apologize for any problems that may arise from these errors. regards, tom lane - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBQnmwGih9+71yA2DNAQJw7AP+LPBaEbRIfi/dfDjXGLiQNcCSePP7eSbL BJOIjp9/yQTG1eCQJqWyjgkBl4DGD0YeLzslAbULQ5M/zRTLPNqXOCzjFZEdOOQP dnkSojMvAa5KMfkCSrxjNtWiC3DPnJtYnm+wzRd2sbTe527laVILEhf+A65jeNxc wXZJKXUP2pU= =cSUm -----END PGP SIGNATURE-----