Usage of weak PRNG in Rclone

1) Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

EUVDB-ID: #VU48568

Risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2020-28924

CWE-ID: CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Exploit availability: No

Description

The vulnerability allows an attacker to decrypt or brute-force passwords.

The vulnerability exists due to Rclone uses a weak random number generator for generating passwords with much less entropy than advertised. An attacker, who is able to obtain the password protected file can decrypt data.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

rclone: 1.49.0 - 1.53.2

CPE2.3

• cpe:2.3:a:rclone.org:rclone:1.49.0:*:*:*:*:*:*:*
• cpe:2.3:a:rclone.org:rclone:1.49.1:*:*:*:*:*:*:*
• cpe:2.3:a:rclone.org:rclone:1.49.2:*:*:*:*:*:*:*

External links

https://github.com/rclone/rclone/issues/4783
https://rclone.org/downloads/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.