Researchers inadvertently release IE7 attack code

Published 11 December 2008

Chinese researchers fail to note that the last security patch released by Microsoft did not take care of a problem they had earlier identified; thinking the problem has been fixed, the researchers release code that might be misused to exploit an unpatched IE 7 vulnerability

In Plato’s Republic the question is posed: “Quis custodiet ipsos custodes?” (who will guard the guardians?) Here is a case showing that the question is still relevant today. Chinese researches admitted that they inadvertently released code that might be misused to exploit an unpatched Internet Explorer 7 vulnerability. Register’s John Leyden reports that scripts to pull off the trick were already on sale in underground forums before the inadvertent release. Still, anything that increases the likelihood of digital delinquents getting their hands on the exploit is unwelcome.

VeriSign’s iDefense security division reports that attack code was up for sale at prices of up to $15,000 through underground forums. Prices are likely to slide following the release of assault code from labs run by KnownSec. Security tools firm eEye reckons the flaw has been the target of exploitation since 15 November.

According to iDefense, KnownSec made the code available after failing to note that last Tuesday’s Microsoft bulletins failed to fix the underlying vulnerability behind the bug, which revolves around IE7’s handling of malformed XML tags. KnownSec offers an explanation of what happened — alas, it is in Mandarin. Here is the first sentence:


Leyden writes that the security flaw affects XP and Vista users, and creates a means to load Trojans or other forms of malware onto even fully patched Windows boxes simply by tricking surfers into visiting maliciously constructed websites. The attack method has been thus far restricted to delivering game password stealers, the Internet Storm Center reports. Microsoft is investigating reports of attacks and considering its options. Leyden notes that the timing of the attack in the run up to the holiday period — and just after a bumper batch of eight bulletins — suggests an out-of-sequence patch might be on order before the next scheduled patch.