Internet Explorer and Excel security updates are the most pressing patching priorities from the bumper crop of 16 bulletins issued as part of Microsoft's June Patch Tuesday updates.
Nine of the bulletins carry a maximum severity of "critical" while the remaining seven earn the lesser tag of "important".
Tuesday also brought critical fixes for Adobe Reader and Oracle for Java, placing an even heavier burden on sys admins.
Security services firm Qualys rates a patch which address 11 vulnerabilities in Internet Explorer (MS11-050) as the most severe security risk in the batch. All supported versions of IE (6-9) will need patching. The updates address a flaw in handling the VMLmarkup language, among other bugs.
Banking Trojan kits feed off browser vulnerabilities, hence the need to patch the IE flaws sooner rather than later before they are targeted by the bad guys behind ZeuS and SpyEye. The Java and Reader security bugs need plugging quickly for much the same reasons.
An update (MS11-045) that tackles eight vulnerabilities in all versions of Excel, including for Mac OS X, is next on the priority list. Redmond ranks the security update as "important" because the end user is required to open an attacker-provided file.
Qualys says that such trickery is all too easily accomplished, and the potential of the flaw to be used in targeted attacks against business users make plugging the flaw a priority.
Another item in the patch batch (MS11-046) tackles a local privilege escalation flaw in the "afd.sys" driver, the only bulletin of the 16 to tackle a vulnerability that's in the wild. The 16 bulletins collectively address 34 vulnerabilities.
Other high priority bulletins MS11-042 and MS11-043 tackle critical flaws in the SMB and DFS clients on Windows. All supported versions of Windows will need patching for one reason or another.
An analysis from Qualys on the updates is here. ®