E.238. Release 7.4.13

E.238.1. Migration to Version 7.4.13

A dump/restore is not required for those running 7.4.X. However, if you are upgrading from a version earlier than 7.4.11, see Section E.240.

Full security against the SQL-injection attacks described in CVE-2006-2313 and CVE-2006-2314 might require changes in application code. If you have applications that embed untrustworthy strings into SQL commands, you should examine them as soon as possible to ensure that they are using recommended escaping techniques. In most cases, applications should be using subroutines provided by libraries or drivers (such as libpq's PQescapeStringConn()) to perform string escaping, rather than relying on ad hoc code to do it.

E.238.2. Changes

• Change the server to reject invalidly-encoded multibyte characters in all cases (Tatsuo, Tom)

  While PostgreSQL has been moving in this direction for some time, the checks are now applied uniformly to all encodings and all textual input, and are now always errors not merely warnings. This change defends against SQL-injection attacks of the type described in CVE-2006-2313.

• Reject unsafe uses of \' in string literals

  As a server-side defense against SQL-injection attacks of the type described in CVE-2006-2314, the server now only accepts '' and not \' as a representation of ASCII single quote in SQL string literals. By default, \' is rejected only when client_encoding is set to a client-only encoding (SJIS, BIG5, GBK, GB18030, or UHC), which is the scenario in which SQL injection is possible. A new configuration parameter backslash_quote is available to adjust this behavior when needed. Note that full security against CVE-2006-2314 might require client-side changes; the purpose of backslash_quote is in part to make it obvious that insecure clients are insecure.

• Modify libpq's string-escaping routines to be aware of encoding considerations and standard_conforming_strings

  This fixes libpq-using applications for the security issues described in CVE-2006-2313 and CVE-2006-2314, and also future-proofs them against the planned changeover to SQL-standard string literal syntax. Applications that use multiple PostgreSQL connections concurrently should migrate to PQescapeStringConn() and PQescapeByteaConn() to ensure that escaping is done correctly for the settings in use in each database connection. Applications that do string escaping "by hand" should be modified to rely on library routines instead.

• Fix some incorrect encoding conversion functions

  win1251_to_iso, alt_to_iso, euc_tw_to_big5, euc_tw_to_mic, mic_to_euc_tw were all broken to varying extents.

• Clean up stray remaining uses of \' in strings (Bruce, Jan)

• Fix bug that sometimes caused OR'd index scans to miss rows they should have returned

• Fix WAL replay for case where a btree index has been truncated

• Fix SIMILAR TO for patterns involving | (Tom)

• Fix server to use custom DH SSL parameters correctly (Michael Fuhr)

• Fix for Bonjour on Intel Macs (Ashley Clark)

• Fix various minor memory leaks