#VU25590 Deserialization of Untrusted Data in JYaml - CVE-2020-8441

Vulnerability identifier: #VU25590

Vulnerability risk: High

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2020-8441

CWE-ID: CWE-502

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
JYaml
Web applications / JS libraries

Vendor: Sean O\'Dell

Description

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

The vulnerability exists due to insecure input validation when processing serialized data passed via the "load()" function. A remote attacker can pass specially crafted data to the application and execute arbitrary code on the target system.

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

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

JYaml: 1.0 - 1.3

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External links
https://gist.github.com/j0lt-github/f5141abcacae63d434ecae211422153a
https://github.com/mbechler/marshalsec
https://github.com/mbechler/marshalsec/blob/master/marshalsec.pdf
https://sourceforge.net/p/jyaml/bugs/

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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. However, proof of concept for this vulnerability is available.