Vulnerability identifier: #VU31885

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-15866

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
mruby
Universal components / Libraries / Scripting languages

Vendor: mruby

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 the mrb_yield_with_class function in vm.c because of incorrect VM stack handling. It can be triggered via the stack_copy function. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger heap-based buffer overflow 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: 2.1.0 - 2.1.1

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External links
http://github.com/mruby/mruby/issues/5042

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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.