Researchers Uncover Extreme Safety Flaws in Main E2EE Cloud Storage Suppliers
Cybersecurity researchers have found extreme cryptographic points in varied end-to-end encrypted (E2EE) cloud storage platforms that may very well be exploited to leak delicate knowledge.
“The vulnerabilities vary in severity: in lots of circumstances a malicious server can inject information, tamper with file knowledge, and even achieve direct entry to plaintext,” ETH Zurich researchers Jonas Hofmann and Kien Tuong Truong said. “Remarkably, lots of our assaults have an effect on a number of suppliers in the identical approach, revealing frequent failure patterns in unbiased cryptographic designs.”
The recognized weaknesses are the results of an evaluation of 5 main suppliers comparable to Sync, pCloud, Icedrive, Seafile, and Tresorit. The devised assault strategies hinge on a malicious server that is beneath an adversary’s management, which might then be used to focus on the service suppliers’ customers.
A short description of the failings uncovered within the cloud storage techniques is as follows –
- Sync, by which a malicious server may very well be used to interrupt the confidentiality of uploaded information, in addition to injecting information and tampering with their content material
- pCloud, by which a malicious server may very well be used to interrupt the confidentiality of uploaded information, in addition to injecting information and tampering with their content material
- Seafile, by which a malicious server may very well be used to speed-up brute-forcing of consumer passwords, in addition to injecting information and tampering with their content material
- Icedrive, by which a malicious server may very well be used to interrupt the integrity of uploaded information, in addition to injecting information and tampering with their content material
- Tresorit, by which a malicious server may very well be used to current non-authentic keys when sharing information and to tamper with some metadata within the storage
These assaults fall into one of many 10 broad courses that violate confidentiality, goal file knowledge and metadata, and permit for injection of arbitrary information –
- Lack of authentication of consumer key materials (Sync and pCloud)
- Use of unauthenticated public keys (Sync and Tresorit)
- Encryption protocol downgrade (Seafile),
- Hyperlink-sharing pitfalls (Sync)
- Use of unauthenticated encryption modes comparable to CBC (Icedrive and Seafile)
- Unauthenticated chunking of information (Seafile and pCloud)
- Tampering with file names and site (Sync, pCloud, Seafile, and Icedrive)
- Tampering with file metadata (impacts all 5 suppliers)
- Injection of folders right into a consumer’s storage by combining the metadata-editing assault and exploiting a quirk within the sharing mechanism (Sync)
- Injection of rogue information right into a consumer’s storage (pCloud)
“Not all of our assaults are subtle in nature, which signifies that they’re inside attain of attackers who should not essentially expert in cryptography. Certainly, our assaults are extremely sensible and could be carried out with out vital sources,” the researchers stated in an accompanying paper.
“Moreover, whereas a few of these assaults should not novel from a cryptographic perspective, they emphasize that E2EE cloud storage as deployed in observe fails at a trivial degree and sometimes doesn’t require extra profound cryptanalysis to interrupt.”
Whereas Icedrive has opted to not tackle the recognized points following accountable disclosure in late April 2024, Sync, Seafile, and Tresorit have acknowledged the report. The Hacker Information has reached out to every of them for additional remark, and we are going to replace the story if we hear again.
The findings come a bit over six months after a bunch of lecturers from King’s School London and ETH Zurich detailed three distinct assaults in opposition to Nextcloud’s E2EE characteristic that may very well be abused to interrupt confidentiality and integrity ensures.
“The vulnerabilities make it trivial for a malicious Nextcloud server to entry and manipulate customers’ knowledge,” the researchers said on the time, highlighting the necessity to deal with all server actions and server-generated inputs as adversarial to deal with the issues.
Again in June 2022, ETH Zurich researchers additionally demonstrated a variety of crucial safety points within the MEGA cloud storage service that may very well be leveraged to interrupt the confidentiality and integrity of consumer knowledge.