#VU31886 Information disclosure in Ruby - CVE-2020-10933

Vulnerability identifier: #VU31886

Vulnerability 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-2020-10933

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ruby
Universal components / Libraries / Scripting languages

Vendor: Ruby

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to BasicSocket#read_nonblock method outputs previous value of the heap instead of copying the requested data. A remote attacker can gain access to sensitive information on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Ruby: 2.5.0 rc1 - 2.6.4

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External links
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/F4TNVTT66VPRMX5UZYSDGSVRXKKDDDU5/
https://security.netapp.com/advisory/ntap-20200625-0001/
https://www.debian.org/security/2020/dsa-4721
https://www.ruby-lang.org/en/news/2020/03/31/heap-exposure-in-socket-cve-2020-10933/

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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.