Remote code execution in mruby

1) Double Free

EUVDB-ID: #VU54556

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-36401

CWE-ID: CWE-415 - Double Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error within the mrb_default_allocf function in mruby. A remote attacker can pass specially crafted data to the application, trigger double free error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

mruby: 2.0.0 - 2.1.2

External links

http://bugs.chromium.org/p/oss-fuzz/issues/detail?id=23801
http://github.com/mruby/mruby/commit/97319697c8f9f6ff27b32589947e1918e3015503
http://github.com/google/oss-fuzz-vulns/blob/main/vulns/mruby/OSV-2020-744.yaml

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.