CVE 2009-0255
The System extension Install tool in TYPO3 4.0.0 through 4.0.9, 4.1.0 through 4.1.7, and 4.2.0 through 4.2.3 creates the encryption key with an insufficiently random seed, which makes it easier for attackers to crack the key.
See the 
CVE page on Mitre.org
for more details.
