Category Archives: Web security

Measuring password re-use empirically

Authentication, Security engineering, Security psychology, Web security

In the aftermath of Anonymous’ revenge hacking of HBGary over the weekend, some enterprising hackers used one of the stolen credentials and some social engineering to gain root access at rootkit.com, which has been down for a few days since. There isn’t much novel about the hack but the dump of rootkit.com’s SQL databases provides another password dataset for research, though an order of magnitude smaller than the Gawker dataset with just 81,000 hashed passwords.

More interestingly, due to the close proximity of the hacks, we can compare the passwords associated with email addresses registered at both Gawker and rootkit.com. This gives an interesting data point on the widely known problem of password re-use. This new data seems to indicate a significantly higher re-use rate than the few previously published estimates. Continue reading Measuring password re-use empirically →

Another Gawker bug: handling non-ASCII characters in passwords

Authentication, Security engineering, Web security

A few weeks ago I detailed how Gawker lost a million of their users’ passwords. Soon after this I found an interesting vulnerability in Gawker’s password deployment involving the handling of non-ASCII characters. Specifically, they didn’t handle them at all until two weeks ago, instead they were mapping all non-ASCII characters to the ASCII ‘?’ prior to hashing them. This not only greatly limited the theoretical space of passwords, but meant that passwords consisting of any n non-ASCII characters were equivalent to ‘?’^n. Native Telugu or Korean speakers with passwords like ‘రహస్య సంకేత పదం’ or ‘비밀번호’ were vulnerable to an attacker simply guessing a string of question marks. An attacker may in fact know in advance that some users are from non-Latin countries (for example by looking at their email addresses) potentially making this more easily exploitable.

Continue reading Another Gawker bug: handling non-ASCII characters in passwords →