![]() The big mistake made by KPM though was using the current system time in seconds as the seed into a Mersenne Twister pseudorandom number generator. It would also require the target to lower their password complexity settings. This issue was only possible in the unlikely event that the attacker knew the user’s account information and the exact time a password had been generated. In October 2020, Kaspersky notified users that some of their passwords may need to be re-generated, with Kaspersky publishing its security advisory on 27 April 2021.Kaspersky has fixed a security issue in Kaspersky Password Manager, which potentially allowed an attacker to find out passwords generated by the tool. Kaspersky was informed of the vulnerability in June 2019, and released the fix version in October that same year. Kaspersky fixed the issues by replacing the Mersenne Twister with BCryptGenRandom function on its Windows version, the research team said. Kaspersky Password Manager versions prior to 9.0.2 Patch F on Windows, 9.2.14.872 on Android, or 9.2.14.31 on iOS were affected. Incidentally, writing this PoC allowed us to spot an out of bounds read during the computation of the frequency of appearance of password chars, which makes passwords a bit stronger that they should have been. It can be used to verify the flaw is indeed present in Windows versions of Kaspersky Password Manager < 9.0.2 Patch F. That means every password generated by vulnerable versions of KPM can be bruteforced in minutes (or in a second if you know approximately the generation time).įinally, we provided a proof of concept that details the full generation method used by KPM. But the major flaw is that this PRNG was seeded with the current time, in seconds. Its internal structure, a Mersenne twister taken from the Boost library, is not suited to generate cryptographic material. We also studied the Kaspersky's PRNG, and showed it was very weak. We showed how to generate secure passwords taking KeePass as an example: simple methods like random draws are secure, as soon as you get rid of the "modulo bias" while peeking a letter from a given range of chars. However, such method lowers the strength of the generated passwords against dedicated tools. This method aimed to create passwords hard to break for standard password crackers. Kaspersky Password Manager used a complex method to generate its passwords. The issue here is that, if hackers know that a target used Kaspersky Password Manager, they can defeat the tool by creating a brute force attack with only these combinations. Like for example, using words like qz or zr. Second, the Kaspersky Password Manager generated passwords using letter grouping rarely found in words. “For example, there are 315619200 seconds between 20, so KPM could generate at most 315619200 passwords for a given charset. “The consequences are obviously bad: every password could be bruteforced,” he said. “It means every instance of Kaspersky Password Manager in the world will generate the exact same password at a given second,” wrote Ledger Donjon head of security research Jean-Baptiste Bédrune in a blog post.īecause the tool has an animation that takes longer than a second when a password is generated, Bédrune said it could be why this issue was not discovered earlier. First, Kaspersky Password Manager used the current time in seconds as the seed for its Mersenne Twister pseudo-random number generator (PRNG).
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