That's pretty much all the company ever thinks The Rest Of Us need to know about updates. Enhanced stability, compatibility and security can't be bad, can it?
Additional information is available if you dig deeper on Apple's web site, though (at the time of writing) you had to work around a link to the wrong support article. The one you need is here.
So what are the highlights?
As expected, several syncing issues have been addressed, in particular iCal syncing with MobileMe, Mail with Notes, and Address Book with Yahoo!.
Talking of third party services, the update also takes care of "issues" that may have been occurring when logging into Gmail.
What else has been fixed? Find out on page 2.
Parental Controls are supposed to work more consistently, including a bug fix involving time limits and full-screen games and fast user switching.
The "reliability and accuracy" of certain widgets has been improved (yes, we would like accurate unit conversion, thank you).
Most of the other changes listed apply to relatively unusual circumstances, such as the Dvorak keyboard layout, network home directories on Mac OS X Server 10.4, and various printing issues.
What about security?
46 fixes are catalogued in total, with just two of them applying exclusively to Mac OS X 10.4. Over half of the issues potentially allow the execution of arbitrary code.
Updated components include Apache, Apple Type Services, BIND, CFNetwork, CoreGraphics, Cscope, CUPS, Disk Image handling (two issues that could lead to arbitrary code execution), enscript, Flash Player, Help Viewer (two issues that could lead to arbitrary code execution), iChat, Unicode string handling, IPSec, Kerberos (multiple issues), Launch Services, libxml, Net-SNMP, Network Time, Networking, OpenSSL, PHP (the update delivers PHP 5.2.8, even though version 5.2.9 was released in February), QuickDraw Manager, ruby, Safari, Spotlight (a vulnerability in the Microsoft Office importer), system_cmds, telnet, WebKit, and X11 (multiple issues).
Some of these deserve a closer look, so please read on.
At least 18 of the issues relate to open source components used by Apple.
document containing a maliciously crafted embedded CFF [Compact Font Format] font may lead to arbitrary code execution."
If this is the bug in question, then some of the criticism of Safari following Pwn2Own was misplaced.
The CoreGraphics bugs are also noteworthy, as they include multiple PDF issues, with at least one apparently similar to a recent Adobe Reader/Acrobat vulnerability. There were reports at the time that other vendors' PDF implementations were also vulnerable, and they have been borne out.
Some of the libxml, Safari and WebKit bugs have also been bundled into Safari 3.2.3 for Windows, Leopard and Tiger; and into the Safari 4 Beta Update for Mac OS X and Windows.
The updates are available via Software Update (Apple Software Update on Windows) or from Apple's Support Downloads page.
File sizes vary widely. The Mac OS X 10.5.7 update varies from 442M for the standalone updater to 951M for the combo updater for the server edition. Depending on the updates already installed, using Software Update may result in a smaller download.
Security Update 2009-002 for Tiger varies from 75M for the PowerPC updater to 203M for the Server Universal version.
Safari 3.2.3 is 40M for Leopard, 26M for Tiger, and 20M for Windows.