A certain type of attack breaks the encryption of the MEGA cloud service. Hackers can thus access files in plain text and download new ones into the user’s personal space.
The MEGA cloud storage platform claims to be unable to decrypt the files we store on the service. A study by researchers at the Swiss Federal Institute of Technology in Zurich says otherwise.
MEGA encryption is not unbreakable
MEGA uses its end-to-end encryption feature as one of its main marketing arguments to stand out from the competition. But this does not appear to be infallible. ” We show that MEGA’s system fails to protect its users against a malicious server and present five separate attacks that together can completely compromise the privacy of users’ files. “, denounces the report.
Experts also point to the possibility that the integrity of the data could be damaged, ” as an attacker can insert malicious files of their choice that pass all client authenticity checks “. They explain that they have developed proof-of-concept versions of all the attacks to demonstrate their exploitability and that this is not just theory.
The researchers sent the results of their work to MEGA in March, which reacted by deploying an update that makes it more difficult to carry out these attacks. But this patch is far from enough, according to those who revealed it. It fixes only one scenario and still leaves several vulnerabilities accessible.
Underlying security flaws
The main problem stems from a security flaw that allows MEGA or an entity that hacked MEGA to recover a user’s entire RSA private key in a limited number of login attempts: 512.
Once the RSA key has been stolen, the attacker has a free hand to carry out other types of attack. One of them allows to decrypt all the communications and all the files of an account, which are therefore available in the clear for hackers.
Another possibility is to upload arbitrary files to the user’s cloud space that are indistinguishable from real ones and potentially contain malware. Finally, a Bleichenbacher attack variant can be carried out to bypass the RSA cipher.
MEGA defends itself by indicating that the attacks described are very hard to perform. The first flaw, which leads to all the other vulnerabilities, requires very specific conditions to be put into practice. But it is not impossible to exploit it.
On the same subject :
Yes, hackers can also hack accounts you haven’t created yet.
Source : The Hacker News
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