Hi list! I am posting my findings here in hopes some may find it interesting, and to provide yet another example of why not to trust browser extensions blindly. This is the top chrome web store search result for "password generator". It has 35,000 users. This was hardly a difficult bug to find, taking just a few minutes, but I was unable to find it online anywhere else.
https://chrome.google.com/webstore/detail/strong-password-generator/emehklffcaphknhhfhadkjhpfapcbpco This password generator contains a logic flaw, which results in some characters appearing more frequently than others in generated passwords. On 2018-03-27, I reported this issue using the "support" section of the extension's page on the chrome web store. On 2018-04-10, I checked back again to discover that the support section for this extension has been switched off. This extension was last updated over 5 years ago. I have concluded that the developer isn't interested in it anymore. In fairness, despite this flaw, this password generator is still probably better than no password generator at all. ------------------------------------------------------------------------------ This line of code is taken from the extension. The array "keys" stores the characters that generated passwords can contain. This is how a random character from the keys array is selected: { var keyPos = Math.round(Math.random() * (keys.length - 1)); } Consider generating passwords with the custom character set "ABC". Math.random()*(keys.length-1) produces a number between 0.0 to 2.0 It shouldn't take long to conclude that a random value between 0.0 and 2.0, when rounded, will produce 1 twice as often as either 0 or 2 Here are some passwords I generated using the character set "ABC": BBBBBBCACCBCBCCABBCBBBCCCAABBAAABABCCBBCBACBACACBBABBBBBCBBBBCBA BACBBABBCBBAAABCBABBBCBABCCCBCCBCBAABBBCBCACABABABBBCBBBCCBBABBC BBBBBABCAAAAABBACCBAAABBACBCBCBBABBBBACBBCBAACBBBCAAACBBACAABAAB ACBABABABCCBBBBBABBBBBACBCACCABBCBCBCCBCABBACACCBCBBBBCABBBABABC A appears 64 times, B appears 127 times, and C appears 65 times _______________________________________________ Sent through the Full Disclosure mailing list https://nmap.org/mailman/listinfo/fulldisclosure Web Archives & RSS: http://seclists.org/fulldisclosure/
